%s

%1$s

%s

' . $record['smtp_debug_info'] . '

` + sections joined by `
` (empty sections dropped).
		 *
		 * @since 1.0.0
		 *
		 * @param string[] $sections {
		 *                           Indexed array of section HTML strings.
		 *
		 * @type string $0 Versions section.
		 * @type string $1 Mailer params + provider debug + (non-SMTP) error.
		 * @type string $2 Debug section. Reserved for backward-compat with the
		 *                           historical signature; no longer populated here.
		 * @type string $3 SMTP debug section (empty for non-SMTP mailers).
		 *                           }
		 */
		$errors = apply_filters( // phpcs:ignore WPForms.PHP.ValidateHooks.InvalidHookName,WPForms.Comments.ParamTagHooks.InvalidParamTagsQuantity -- Public hook name + 1-arg signature preserved for backward compatibility after relocation from TestTab.
			'wp_mail_smtp_admin_test_get_debug_messages',
			[
				$versions_text,
				$mailer_text,
				// Reserved slot to preserve the historical filter signature.
				'',
				$smtp_text,
			]
		);

		return '
' . implode( '
', array_filter( $errors ) ) . '
';
	}

	/**
	 * Render the `description` block from `get_local_failure_info()` as the cause
	 * statement at the top of a Doc Not Present banner body.
	 *
	 * @since 4.9.0
	 *
	 * @param array $record Failure record.
	 */
	private function print_failure_cause( $record ) {

		$info        = $this->get_local_failure_info( $record );
		$description = isset( $info['description'] ) && is_array( $info['description'] ) ? $info['description'] : [];

		if ( empty( $description ) ) {
			return;
		}

		$allowed_tags = [
			'a'      => [
				'href'   => [],
				'rel'    => [],
				'target' => [],
			],
			'strong' => [],
			'b'      => [],
			'em'     => [],
			'i'      => [],
			'code'   => [],
		];

		echo '
';
		printf(
			'
%s
',
			esc_html__( 'Typically this error is returned for one of the following reasons:', 'wp-mail-smtp' )
		);

		echo '
';
		foreach ( $description as $cause ) {
			echo '
' . wp_kses( $cause, $allowed_tags ) . '
'; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped
		}
		echo '
';
		echo '
';
	}

	/**
	 * Returns debug information for detection, processing, and display.
	 *
	 * Pattern-matches the failure record's error text against a registry of known
	 * issue signatures and returns the matched (title, description, steps) bundle,
	 * or a generic default when nothing matches.
	 *
	 * @since 4.9.0
	 *
	 * @param array $record EmailSendingDebug record for a single connection.
	 *
	 * @return array
	 */
	private function get_local_failure_info( $record ) { // phpcs:ignore Generic.Metrics.CyclomaticComplexity.MaxExceeded,Generic.Metrics.NestingLevel.MaxExceeded -- Pattern-matching switch over a static registry of failure signatures; flattening would scatter the registry.

		$details = [
			// [any] - cURL error 60/77.
			[
				'mailer'      => 'any',
				'errors'      => [
					[ 'cURL error 60' ],
					[ 'cURL error 77' ],
				],
				'title'       => esc_html__( 'SSL certificate issue.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'Your server cannot establish secure HTTPS connections.', 'wp-mail-smtp' ),
					esc_html__( 'Your server\'s CA certificate bundle is outdated.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					esc_html__( 'Contact your web hosting provider and inform them your site has an issue with SSL certificates.', 'wp-mail-smtp' ),
					esc_html__( 'Share the Error Log below with them so they can resolve the issue.', 'wp-mail-smtp' ),
				],
			],
			// [any] - cURL error 6/7.
			[
				'mailer'      => 'any',
				'errors'      => [
					[ 'cURL error 6' ],
					[ 'cURL error 7' ],
				],
				'title'       => esc_html__( 'Could not connect to host.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'Your web server is blocking outbound connections.', 'wp-mail-smtp' ),
					esc_html__( 'Your SMTP host is rejecting the connection.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					esc_html__( 'Contact your web hosting provider and ask them to verify your server can make outbound connections, and whether a firewall or security policy may be blocking them.', 'wp-mail-smtp' ),
					esc_html__( 'If using the "Other SMTP" Mailer, triple-check your SMTP settings (host, email, password) and confirm with your SMTP host that they accept outside connections using those settings.', 'wp-mail-smtp' ),
				],
			],
			// [sendgrid] - cURL error 18 - potential incorrect API key.
			[
				'mailer'      => 'sendgrid',
				'errors'      => [
					[ 'cURL error 18' ],
				],
				'title'       => esc_html__( 'Invalid SendGrid API key.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'Your SendGrid API key is invalid or has been revoked.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					esc_html__( 'Go to the WP Mail SMTP plugin Settings page.', 'wp-mail-smtp' ),
					esc_html__( 'Make sure your API Key in the SendGrid mailer settings is correct and valid.', 'wp-mail-smtp' ),
					esc_html__( 'Save the plugin settings.', 'wp-mail-smtp' ),
					esc_html__( 'If updating the API Key doesn\'t resolve this issue, please contact our support.', 'wp-mail-smtp' ),
				],
			],
			// [any] - cURL error XX (other).
			[
				'mailer'      => 'any',
				'errors'      => [
					[ 'cURL error' ],
				],
				'title'       => esc_html__( 'Could not connect to your host.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'Your server is unable to make outbound HTTP connections.', 'wp-mail-smtp' ),
					esc_html__( 'Your hosting provider is blocking the request.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					esc_html__( 'Contact your web hosting provider and inform them you are having issues making outbound connections.', 'wp-mail-smtp' ),
					esc_html__( 'Share the Error Log below with them so they can resolve the issue.', 'wp-mail-smtp' ),
				],
			],
			// [smtp] - SMTP Error: Count not authenticate.
			[
				'mailer'      => 'smtp',
				'errors'      => [
					[ 'SMTP Error: Could not authenticate.' ],
				],
				'title'       => esc_html__( 'Could not authenticate your SMTP account.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'Your SMTP username or password is incorrect.', 'wp-mail-smtp' ),
					esc_html__( 'Your SMTP host requires a different authentication method.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					esc_html__( 'Triple-check your SMTP settings including host address, email, and password. If you have recently reset your password you will need to update the settings.', 'wp-mail-smtp' ),
					esc_html__( 'Contact your SMTP host to confirm you are using the correct username and password.', 'wp-mail-smtp' ),
					esc_html__( 'Verify with your SMTP host that your account has permissions to send emails using outside connections.', 'wp-mail-smtp' ),
					sprintf(
						wp_kses( /* translators: %s - URL to the wpmailsmtp.com doc page. */
							__( 'Visit our documentation for additional tips on how to resolve this error.', 'wp-mail-smtp' ),
							[
								'a' => [
									'href'   => [],
									'target' => [],
									'rel'    => [],
								],
							]
						),
						esc_url( wp_mail_smtp()->get_utm_url( 'https://wpmailsmtp.com/docs/how-to-set-up-the-other-smtp-mailer-in-wp-mail-smtp/#auth-type', [ 'medium' => 'email-test', 'content' => 'Other SMTP auth debug - our documentation' ] ) ) // phpcs:ignore WordPress.Arrays.ArrayDeclarationSpacing.AssociativeArrayFound
					),
				],
			],
			// [smtp] - Sending bulk email, hitting rate limit.
			[
				'mailer'      => 'smtp',
				'errors'      => [
					[ 'We do not authorize the use of this system to transport unsolicited' ],
				],
				'title'       => esc_html__( 'Error due to unsolicited and/or bulk e-mail.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'You are sending more emails than your SMTP host allows.', 'wp-mail-smtp' ),
					esc_html__( 'Your message was flagged as spam by the SMTP host.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					esc_html__( 'Reduce the recipient count per email: keep single emails to under 10 recipients.', 'wp-mail-smtp' ),
					esc_html__( 'Install an email-logging plugin to inspect your TO, CC, and BCC recipients.', 'wp-mail-smtp' ),
					esc_html__( 'Contact your SMTP host to ask about sending and rate limits.', 'wp-mail-smtp' ),
					esc_html__( 'Verify with them that your SMTP account is in good standing and has not been flagged.', 'wp-mail-smtp' ),
				],
			],
			// [smtp] - Unauthenticated senders not allowed.
			[
				'mailer'      => 'smtp',
				'errors'      => [
					[ 'Unauthenticated senders not allowed' ],
				],
				'title'       => esc_html__( 'Unauthenticated senders are not allowed.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'Your SMTP host requires authentication, but it is disabled in the plugin settings.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					esc_html__( 'Go to the WP Mail SMTP plugin Settings page.', 'wp-mail-smtp' ),
					esc_html__( 'Enable Authentication.', 'wp-mail-smtp' ),
					esc_html__( 'Enter the correct SMTP Username (usually an email address) and Password in the appropriate fields.', 'wp-mail-smtp' ),
				],
			],
			// [smtp] - certificate verify failed.
			// Has to be defined before "SMTP connect() failed" error, since this is a more specific error,
			// which contains the "SMTP connect() failed" error message as well.
			[
				'mailer'      => 'smtp',
				'errors'      => [
					[ 'certificate verify failed' ],
				],
				'title'       => esc_html__( 'Misconfigured server certificate.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'The SMTP host\'s SSL certificate is misconfigured or expired.', 'wp-mail-smtp' ),
					esc_html__( 'Your server\'s OpenSSL CA bundle is outdated.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					esc_html__( 'Verify that the host\'s SSL certificate is valid.', 'wp-mail-smtp' ),
					sprintf(
						wp_kses( /* translators: %s - URL to the PHP openssl manual. */
							__( 'Contact your hosting support and share the Error Log below along with this link.', 'wp-mail-smtp' ),
							[
								'a' => [
									'href'   => [],
									'target' => [],
									'rel'    => [],
								],
							]
						),
						'https://www.php.net/manual/en/migration56.openssl.php'
					),
				],
			],
			// [smtp] - SMTP connect() failed.
			[
				'mailer'      => 'smtp',
				'errors'      => [
					[ 'SMTP connect() failed' ],
				],
				'title'       => esc_html__( 'Could not connect to the SMTP host.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'Your SMTP settings are incorrect (wrong port, security setting, or host).', 'wp-mail-smtp' ),
					esc_html__( 'Your web server is blocking the outbound connection.', 'wp-mail-smtp' ),
					esc_html__( 'Your SMTP host is rejecting the connection.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					esc_html__( 'Triple-check your SMTP settings: host, email, password, port, and security.', 'wp-mail-smtp' ),
					wp_kses(
						__( 'Contact your web hosting provider and ask them to verify your server can connect to your SMTP host on the configured port and encryption, and whether a firewall or security policy may be blocking the connection. Many shared hosts block certain ports. Note: this is the most common cause of this issue.', 'wp-mail-smtp' ),
						[
							'strong' => [],
						]
					),
					esc_html__( 'Contact your SMTP host to confirm you are using the correct username and password.', 'wp-mail-smtp' ),
					esc_html__( 'Verify with your SMTP host that your account has permissions to send emails using outside connections.', 'wp-mail-smtp' ),
				],
			],
			// [mailgun] - Please activate your Mailgun account.
			[
				'mailer'      => 'mailgun',
				'errors'      => [
					[ 'Please activate your Mailgun account' ],
				],
				'title'       => esc_html__( 'Mailgun failed.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'Your Mailgun account has not been activated.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					esc_html__( 'Check the inbox you used to create your Mailgun account and click the activation link in the email from Mailgun.', 'wp-mail-smtp' ),
					esc_html__( 'If you do not see the activation email, go to your Mailgun control panel and resend it.', 'wp-mail-smtp' ),
				],
			],
			// [mailgun] - Forbidden.
			[
				'mailer'      => 'mailgun',
				'errors'      => [
					[ 'Forbidden' ],
				],
				'title'       => esc_html__( 'Mailgun failed.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'Your Mailgun API key is incorrect.', 'wp-mail-smtp' ),
					esc_html__( 'Your Mailgun domain name is incorrect.', 'wp-mail-smtp' ),
					esc_html__( 'Your Mailgun region is incorrect.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					sprintf(
						wp_kses( /* translators: %1$s - Mailgun API Key area URL. */
							__( 'Go to your Mailgun account and verify that your Mailgun API Key is correct.', 'wp-mail-smtp' ),
							[
								'a' => [
									'href'   => [],
									'rel'    => [],
									'target' => [],
								],
							]
						),
						'https://app.mailgun.com/settings/api_security'
					),
					sprintf(
						wp_kses( /* translators: %1$s - Mailgun domains area URL. */
							__( 'Verify your Domain Name is correct.', 'wp-mail-smtp' ),
							[
								'a' => [
									'href'   => [],
									'rel'    => [],
									'target' => [],
								],
							]
						),
						'https://app.mailgun.com/mg/sending/domains'
					),
					esc_html__( 'Verify your domain Region is correct.', 'wp-mail-smtp' ),
				],
			],
			// [mailgun] - Free accounts are for test purposes only.
			[
				'mailer'      => 'mailgun',
				'errors'      => [
					[ 'Free accounts are for test purposes only' ],
				],
				'title'       => esc_html__( 'Mailgun failed.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'Your Mailgun domain has not been verified.', 'wp-mail-smtp' ),
					esc_html__( 'Your Mailgun account is still on the free trial plan.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					sprintf(
						wp_kses( /* translators: %s - Mailgun documentation URL. */
							__( 'Go to our how-to guide for setting up Mailgun with WP Mail SMTP.', 'wp-mail-smtp' ),
							[
								'a' => [
									'href'   => [],
									'rel'    => [],
									'target' => [],
								],
							]
						),
						esc_url( wp_mail_smtp()->get_utm_url( 'https://wpmailsmtp.com/docs/how-to-set-up-the-mailgun-mailer-in-wp-mail-smtp/', [ 'medium' => 'email-test', 'content' => 'Mailgun with WP Mail SMTP' ] ) ) // phpcs:ignore WordPress.Arrays.ArrayDeclarationSpacing.AssociativeArrayFound
					),
					esc_html__( 'Complete the steps in section "2. Verify Your Domain".', 'wp-mail-smtp' ),
				],
			],
			// [gmail] - 401: Login Required.
			[
				'mailer'      => 'gmail',
				'errors'      => [
					[ '401', 'Login Required' ],
				],
				'title'       => esc_html__( 'Google API Error.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'Gmail authorization has not been completed.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					esc_html__( 'Go to the WP Mail SMTP plugin Settings page.', 'wp-mail-smtp' ),
					esc_html__( 'Click the "Allow plugin to send emails using your Google account" button.', 'wp-mail-smtp' ),
					esc_html__( 'On the Google authorization screen, click "Allow" to grant the plugin permission to send emails on your behalf.', 'wp-mail-smtp' ),
				],
			],
			// [gmail] - 400: Recipient address required.
			[
				'mailer'      => 'gmail',
				'errors'      => [
					[ '400', 'Recipient address required' ],
				],
				'title'       => esc_html__( 'Google API Error.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'The recipient email address is empty or invalid.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					esc_html__( 'Check the "Send To" email address and confirm it is valid and not empty.', 'wp-mail-smtp' ),
					sprintf( /* translators: 1 - correct email address example. 2 - incorrect email address example. */
						esc_html__( 'It should look like %1$s. These are invalid: %2$s.', 'wp-mail-smtp' ),
						'info@example.com',
						'info@localhost, info@192.168.1.1'
					),
					esc_html__( 'If you are generating the email yourself, make sure it includes a TO header.', 'wp-mail-smtp' ),
				],
			],
			// [gmail] - Token has been expired or revoked.
			[
				'mailer'      => 'gmail',
				'errors'      => [
					[ 'invalid_grant', 'Token has been expired or revoked' ],
				],
				'title'       => esc_html__( 'Google API Error.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'Your Gmail OAuth refresh token has expired.', 'wp-mail-smtp' ),
					esc_html__( 'Access was revoked from your Google account.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					esc_html__( 'Go to the WP Mail SMTP plugin Settings page and click the "Remove OAuth Connection" button.', 'wp-mail-smtp' ),
					esc_html__( 'Then click the "Allow plugin to send emails using your Google account" button and re-enable access.', 'wp-mail-smtp' ),
				],
			],
			// [gmail] - Code was already redeemed.
			[
				'mailer'      => 'gmail',
				'errors'      => [
					[ 'invalid_grant', 'Code was already redeemed' ],
				],
				'title'       => esc_html__( 'Google API Error.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'The Google authorization code has already been used.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					esc_html__( 'Do not manually clean up the plugin options to retry the "Allow..." step.', 'wp-mail-smtp' ),
					esc_html__( 'Reinstall the plugin with clean plugin data enabled on the Misc page. This will remove all plugin options so you can safely retry.', 'wp-mail-smtp' ),
					esc_html__( 'Make sure there is no aggressive caching on admin pages, or clear the cache between attempts.', 'wp-mail-smtp' ),
				],
			],
			// [gmail] - 400: Mail service not enabled.
			[
				'mailer'      => 'gmail',
				'errors'      => [
					[ '400', 'Mail service not enabled' ],
				],
				'title'       => esc_html__( 'Google API Error.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'Your Google Workspace trial period has expired.', 'wp-mail-smtp' ),
					esc_html__( 'Gmail is not enabled in your Google Workspace account.', 'wp-mail-smtp' ),
					esc_html__( 'The Gmail API is not enabled in your Google Cloud project.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					sprintf(
						wp_kses( /* translators: %s - Google Workspace Admin area URL. */
							__( 'Verify in Google Workspace Admin that your trial period has not expired.', 'wp-mail-smtp' ),
							[
								'a' => [
									'href'   => [],
									'rel'    => [],
									'target' => [],
								],
							]
						),
						'https://admin.google.com'
					),
					sprintf(
						wp_kses( /* translators: %s - Google Workspace Admin area URL. */
							__( 'In the Apps list of Google Workspace Admin, confirm that Gmail is enabled.', 'wp-mail-smtp' ),
							[
								'a' => [
									'href'   => [],
									'rel'    => [],
									'target' => [],
								],
							]
						),
						'https://admin.google.com'
					),
					sprintf(
						wp_kses( /* translators: %s - Google Cloud Console URL. */
							__( 'Enable the Gmail API in your project from Google Cloud Console.', 'wp-mail-smtp' ),
							[
								'a' => [
									'href'   => [],
									'rel'    => [],
									'target' => [],
								],
							]
						),
						'https://console.cloud.google.com/'
					),
				],
			],
			// [gmail] - 403: Project X is not found and cannot be used for API calls.
			[
				'mailer'      => 'gmail',
				'errors'      => [
					[ '403', 'is not found and cannot be used for API calls' ],
				],
				'title'       => esc_html__( 'Google API Error.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'The Google Cloud project linked to your Client ID/Secret no longer exists.', 'wp-mail-smtp' ),
					esc_html__( 'The Gmail API is not enabled on the project.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					esc_html__( 'Make sure the Client ID/Secret in your settings corresponds to a project that has the Gmail API enabled.', 'wp-mail-smtp' ),
					sprintf(
						wp_kses( /* translators: %s - Gmail documentation URL. */
							esc_html__( 'Follow our Gmail tutorial to ensure your project and credentials are configured correctly.', 'wp-mail-smtp' ),
							[
								'a' => [
									'href'   => [],
									'rel'    => [],
									'target' => [],
								],
							]
						),
						esc_url( wp_mail_smtp()->get_utm_url( 'https://wpmailsmtp.com/docs/how-to-set-up-the-gmail-mailer-in-wp-mail-smtp/', [ 'medium' => 'email-test', 'content' => 'Gmail tutorial' ] ) ) // phpcs:ignore WordPress.Arrays.ArrayDeclarationSpacing.AssociativeArrayFound
					),
				],
			],
			// [gmail] - The OAuth client was disabled.
			[
				'mailer'      => 'gmail',
				'errors'      => [
					[ 'disabled_client', 'The OAuth client was disabled' ],
				],
				'title'       => esc_html__( 'Google API Error.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'Your Google OAuth client has been disabled.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					esc_html__( 'Make sure your Client ID/Secret corresponds to a project that has the Gmail API enabled.', 'wp-mail-smtp' ),
					esc_html__( 'In Google Cloud Console, re-enable the disabled OAuth client, or create a new OAuth client and update the plugin settings with the new Client ID/Secret.', 'wp-mail-smtp' ),
				],
			],
			// [SMTP.com] - The "channel - not found" issue.
			[
				'mailer'      => 'smtpcom',
				'errors'      => [
					[ 'channel - not found' ],
				],
				'title'       => esc_html__( 'SMTP.com API Error.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'Your SMTP.com Sender Name is incorrect.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					esc_html__( 'Please make sure you entered an accurate Sender Name in WP Mail SMTP plugin settings.', 'wp-mail-smtp' ),
				],
			],
			// [gmail] - GuzzleHttp requires cURL, the allow_url_fopen ini setting, or a custom HTTP handler.
			[
				'mailer'      => 'gmail',
				'errors'      => [
					[ 'GuzzleHttp requires cURL, the allow_url_fopen ini setting, or a custom HTTP handler' ],
				],
				'title'       => esc_html__( 'GuzzleHttp requirements.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'The cURL PHP extension is disabled on your server.', 'wp-mail-smtp' ),
					esc_html__( 'The allow_url_fopen PHP setting is disabled on your server.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					esc_html__( 'Edit your php.ini file on your hosting server.', 'wp-mail-smtp' ),
					esc_html__( '(Recommended) Enable the cURL PHP extension by adding extension=curl to php.ini.', 'wp-mail-smtp' ),
					esc_html__( '(Or) Enable allow_url_fopen by adding allow_url_fopen = On to php.ini.', 'wp-mail-smtp' ),
					esc_html__( 'If you cannot edit php.ini yourself, share the Error Log below with your hosting support and ask them to make this change.', 'wp-mail-smtp' ),
				],
			],
			// [sparkpost] - Forbidden.
			[
				'mailer'      => 'sparkpost',
				'errors'      => [
					[ 'Forbidden' ],
				],
				'title'       => esc_html__( 'SparkPost API failed.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'Your SparkPost API key is incorrect.', 'wp-mail-smtp' ),
					esc_html__( 'Your SparkPost API key is missing the "Transmissions: Read/Write" permission.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					sprintf(
						wp_kses( /* translators: %1$s - SparkPost API Keys area URL, %2$s - SparkPost EU API Keys area URL. */
							__( 'Go to your SparkPost account or SparkPost EU account and verify that your API key is correct.', 'wp-mail-smtp' ),
							[
								'a' => [
									'href'   => [],
									'rel'    => [],
									'target' => [],
								],
							]
						),
						'https://app.sparkpost.com/account/api-keys',
						'https://app.eu.sparkpost.com/account/api-keys'
					),
					esc_html__( 'Verify that your API key has "Transmissions: Read/Write" permission.', 'wp-mail-smtp' ),
				],
			],
			// [sparkpost] - Unauthorized.
			[
				'mailer'      => 'sparkpost',
				'errors'      => [
					[ 'Unauthorized' ],
				],
				'title'       => esc_html__( 'SparkPost API failed.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'Your SparkPost account region is incorrect.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					esc_html__( 'Verify that your SparkPost account region is selected in WP Mail SMTP settings.', 'wp-mail-smtp' ),
				],
			],
		];

		/**
		 * [any] - PHP 7.4.x and PCRE library issues.
		 *
		 * @see https://wordpress.org/support/topic/cant-send-emails-using-php-7-4/
		 */
		if (
			version_compare( phpversion(), '7.4', '>=' ) &&
			defined( 'PCRE_VERSION' ) &&
			version_compare( PCRE_VERSION, '10.0', '>' ) &&
			version_compare( PCRE_VERSION, '10.32', '<=' )
		) {
			$details[] = [
				'mailer'      => 'any',
				'errors'      => [
					[ 'Invalid address:  (setFrom)' ],
				],
				'title'       => esc_html__( 'PCRE library issue.', 'wp-mail-smtp' ),
				'description' => [
					esc_html__( 'Your server is running PHP 7.4.x with an outdated libpcre2 library (version 10.32 or earlier) that fails email address validation.', 'wp-mail-smtp' ),
				],
				'steps'       => [
					esc_html__( 'Contact your web hosting provider and inform them you are having issues with the libpcre2 library on PHP 7.4. They should be able to resolve this.', 'wp-mail-smtp' ),
					esc_html__( 'As a temporary workaround, you can downgrade to PHP 7.3 on your server.', 'wp-mail-smtp' ),
				],
			];
		}

		$mailer_slug = isset( $record['mailer'] ) ? $record['mailer'] : '';
		$haystack    = implode(
			"\n",
			array_filter(
				[
					isset( $record['error_message'] ) ? $record['error_message'] : '',
					isset( $record['mailer_debug_info'] ) ? $record['mailer_debug_info'] : '',
					isset( $record['smtp_debug_info'] ) ? $record['smtp_debug_info'] : '',
				]
			)
		);

		// Error detection logic.
		foreach ( $details as $data ) {

			// Check for appropriate mailer.
			if ( $data['mailer'] !== 'any' && $mailer_slug !== $data['mailer'] ) {
				continue;
			}

			$match = false;

			// Attempt to detect errors.
			foreach ( $data['errors'] as $error_group ) {
				foreach ( $error_group as $error_message ) {
					$match = strpos( $haystack, $error_message ) !== false;

					if ( ! $match ) {
						break;
					}
				}
				if ( $match ) {
					break;
				}
			}

			if ( $match ) {
				return $data;
			}
		}

		// Return defaults.
		return [
			'title'       => esc_html__( 'An issue was detected.', 'wp-mail-smtp' ),
			'description' => [
				esc_html__( 'Your plugin settings are incorrect (wrong SMTP settings, invalid Mailer configuration, etc.).', 'wp-mail-smtp' ),
				esc_html__( 'Your web server is blocking the connection.', 'wp-mail-smtp' ),
				esc_html__( 'Your host is rejecting the connection.', 'wp-mail-smtp' ),
			],
			'steps'       => [
				esc_html__( 'Triple-check your plugin settings, reconfigure if needed to make sure everything is correct.', 'wp-mail-smtp' ),
				wp_kses(
					__( 'Contact your web hosting provider and ask them to verify your server can make outside connections, and whether a firewall or security policy may be blocking them. Many shared hosts block certain ports. Note: this is the most common cause of this issue.', 'wp-mail-smtp' ),
					[
						'strong' => [],
					]
				),
			],
		];
	}

	/**
	 * Render the "Need Help?" sub-section inside the banner body.
	 *
	 * Renders the matched issue's `steps` (or the default bundle's steps when
	 * nothing matched), followed by the SendLayer Quick Connect upsell (Lite
	 * only), the White Glove Setup bullet, and an edition-specific support
	 * line. Steps are suppressed when a troubleshoot doc URL is available,
	 * since the doc covers the same ground.
	 *
	 * @since 4.9.0
	 *
	 * @param array $record    Failure record.
	 * @param array $doc_state Output of {@see resolve_doc_state()}.
	 */
	private function print_need_help( $record, $doc_state ) {

		$bullets = [];

		$allowed_tags = [
			'a'      => [
				'href'   => [],
				'rel'    => [],
				'target' => [],
				'class'  => [],
			],
			'strong' => [],
			'b'      => [],
			'em'     => [],
			'i'      => [],
			'br'     => [],
			'code'   => [],
			'ul'     => [],
			'li'     => [],
			'span'   => [
				'class' => [],
			],
		];

		if ( $doc_state['state'] !== 'doc_present' ) {
			$info  = $this->get_local_failure_info( $record );
			$steps = isset( $info['steps'] ) && is_array( $info['steps'] ) ? $info['steps'] : [];

			foreach ( $steps as $step ) {
				$bullets[] = wp_kses( $step, $allowed_tags );
			}
		}

		$primary_mailer = (string) Options::init()->get( 'mail', 'mailer' );
		$record_mailer  = isset( $record['mailer'] ) ? (string) $record['mailer'] : '';

		if ( $primary_mailer !== 'sendlayer' && $record_mailer !== 'sendlayer' ) {
			$bullets[] = wp_kses(
				__( 'Resolve your email sending issues with SendLayer, and send your first 200 emails for free with just a few clicks!', 'wp-mail-smtp' ),
				$allowed_tags
			);
		}

		$bullets[] = sprintf(
			wp_kses( /* translators: %s - White Glove Setup URL. */
				__( 'Need hands-on help? Our White Glove Setup handles everything for you, just share your site details and we’ll do the rest.', 'wp-mail-smtp' ),
				$allowed_tags
			),
			// TODO: Verify that this White Glove Setup URL is correct and up to date before release.
			esc_url( wp_mail_smtp()->get_utm_url( 'https://wpmailsmtp.com/white-glove-setup/', [ 'medium' => 'email-sending-errors-banner', 'content' => 'White Glove Setup' ] ) ) // phpcs:ignore WordPress.Arrays.ArrayDeclarationSpacing.AssociativeArrayFound
		);

		if ( $doc_state['state'] !== 'doc_present' ) {
			if ( wp_mail_smtp()->is_pro() ) {
				$bullets[] = sprintf(
					wp_kses( /* translators: %s - WPMailSMTP.com support URL. */
						__( 'Still stuck? Please log in to your WP Mail SMTP account and submit a support ticket with the error log.', 'wp-mail-smtp' ),
						$allowed_tags
					),
					esc_url( wp_mail_smtp()->get_utm_url( 'https://wpmailsmtp.com/account/support/', [ 'medium' => 'email-sending-errors-banner', 'content' => 'submit a support ticket' ] ) ) // phpcs:ignore WordPress.Arrays.ArrayDeclarationSpacing.AssociativeArrayFound
				);
			} else {
				$bullets[] = sprintf(
					wp_kses( /* translators: %1$s - wordpress.org support forum URL, %2$s - upgrade-to-Pro URL. */
						__( 'Still stuck? Get priority support by Upgrading to Pro or create a support thread along with the error log on WordPress.org forums. ', 'wp-mail-smtp' ),
						$allowed_tags
					),
					esc_url( wp_mail_smtp()->get_upgrade_link( [ 'medium' => 'email-sending-errors-banner', 'content' => 'Upgrading to Pro' ] ) ), // phpcs:ignore WordPress.Arrays.ArrayDeclarationSpacing.AssociativeArrayFound
					'https://wordpress.org/support/plugin/wp-mail-smtp/',
				);
			}
		}

		echo '
';
		printf(
			'
%s
',
			esc_html__( 'Need Help?', 'wp-mail-smtp' )
		);
		echo '
';
		foreach ( $bullets as $bullet ) {
			echo '
' . $bullet . '
'; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped
		}
		echo '
';
		echo '
';
	}

	/**
	 * Render the verbose one-liner notice for an additional connection. On the
	 * General Settings page these stack vertically under the primary banner.
	 *
	 * @since 4.9.0
	 *
	 * @param array               $record     Failure record.
	 * @param ConnectionInterface $connection Additional connection object.
	 */
	private function print_additional_connection_note( $record, $connection ) {

		$connection_id   = $connection->get_id();
		$connection_name = $connection->get_name();

		if ( $connection_name === '' ) {
			$connection_name = esc_html__( 'an additional connection', 'wp-mail-smtp' );
		}

		$severity_class = ( isset( $record['status'] ) && $record['status'] === 'sent' )
			? 'notice-warning'
			: 'notice-error';

		$edit_url = add_query_arg(
			[
				'page'          => 'wp-mail-smtp',
				'tab'           => 'connections',
				'mode'          => 'edit',
				'connection_id' => $connection_id,
			],
			admin_url( 'admin.php' )
		);

		$is_backup     = $this->is_backup_connection( $connection_id );
		$name_html     = '' . esc_html( $connection_name ) . '';
		$rescued       = ( isset( $record['status'] ) && $record['status'] === 'sent' );
		$is_test       = ( isset( $record['context'] ) && $record['context'] === 'test' );
		$test_word     = '' . esc_html__( 'test', 'wp-mail-smtp' ) . '';
		$backup_prefix = $is_backup
			? sprintf( /* translators: %s: connection name, bolded. */
				__( 'your backup connection %s', 'wp-mail-smtp' ),
				$name_html
			)
			: $name_html;

		if ( $rescued ) {
			$copy = sprintf( /* translators: %s: connection display name. */
				__( '%s failed to send the last email. Your backup connection sent it successfully.', 'wp-mail-smtp' ),
				$backup_prefix
			);
		} elseif ( $is_test ) {
			$copy = sprintf( /* translators: %1$s: literal word "test", bolded. %2$s: connection display name. */
				__( 'The last %1$s email your site attempted to send via %2$s was unsuccessful.', 'wp-mail-smtp' ),
				$test_word,
				$name_html
			);
		} else {
			$copy = sprintf( /* translators: %s: connection display name. */
				__( 'The last email your site attempted to send via %s was unsuccessful.', 'wp-mail-smtp' ),
				$backup_prefix
			);
		}

		$manage_html = wp_kses(
			sprintf(
				/* translators: %s - link to the Additional Connection Settings page. */
				__( 'Manage it on the %s page.', 'wp-mail-smtp' ),
				sprintf(
					'%s',
					esc_url( $edit_url ),
					esc_html__( 'Additional Connection Settings', 'wp-mail-smtp' )
				)
			),
			[ 'a' => [ 'href' => [] ] ]
		);

		printf(
			'
' .
			'
%3$s %4$s
' .
			'
',
			esc_attr( $severity_class ),
			esc_attr( $connection_id ),
			wp_kses( $copy, [ 'strong' => [] ] ),
			$manage_html // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped
		);
	}

	/**
	 * Whether a given additional-connection id is currently configured as the
	 * backup connection. Returns false when Pro is inactive or no backup is set.
	 *
	 * @since 4.9.0
	 *
	 * @param string $connection_id Connection ID.
	 *
	 * @return bool
	 */
	private function is_backup_connection( $connection_id ) {

		$backup_id = Options::init()->get( 'backup_connection', 'connection_id' );

		return ! empty( $backup_id ) && $backup_id === $connection_id;
	}

	/**
	 * Whether we're on Tools > Email Test tab.
	 *
	 * Handles the implicit-default case: {@see \WPMailSMTP\Admin\Pages\Tools::$default_tab}
	 * is `'test'`, so a missing `?tab=…` param on the tools page still means we're
	 * on the test tab. `Area::is_admin_page( 'test' )` can't detect this because
	 * `'test'` isn't a top-level registered page, and `Area::get_current_tab()`
	 * only resolves the tab for the general page.
	 *
	 * @since 4.9.0
	 *
	 * @return bool
	 */
	private function is_test_tab() {

		if ( ! wp_mail_smtp()->get_admin()->is_admin_page( 'tools' ) ) {
			return false;
		}

		// phpcs:ignore WordPress.Security.NonceVerification.Recommended
		$tab = isset( $_GET['tab'] ) ? sanitize_key( wp_unslash( $_GET['tab'] ) ) : '';

		return $tab === '' || $tab === 'test';
	}

	/**
	 * Whether we're currently viewing the Additional Connections tab on Settings.
	 *
	 * Settings → Connections is `page=wp-mail-smtp&tab=connections`; the AC tab is
	 * NOT a registered WP admin page slug, so `is_admin_page('connections')` falls
	 * back to matching the Settings page (any tab). This helper does the
	 * tab-aware check.
	 *
	 * @since 4.9.0
	 *
	 * @return bool
	 */
	private function is_connections_tab() {

		if ( ! wp_mail_smtp()->get_admin()->is_admin_page( 'general' ) ) {
			return false;
		}

		// phpcs:ignore WordPress.Security.NonceVerification.Recommended
		$tab = isset( $_GET['tab'] ) ? sanitize_key( wp_unslash( $_GET['tab'] ) ) : '';

		return $tab === 'connections';
	}
}