Alternate SMTP WP Plugin Documentation

Overview

The Alternate SMTP WP Plugin is designed to ensure the reliability of email delivery from your WordPress site, particularly when using third-party SMTP services such as Mailgun, Mailtrap, Mailchimp, and similar services. If the primary SMTP service fails for any reason, this plugin automatically switches to a backup SMTP service, ensuring uninterrupted email delivery.

Purpose

The main purpose of this plugin is to provide a fallback mechanism for sending emails when the primary SMTP service is unavailable. If the first SMTP service (e.g., Mailgun) fails, the plugin will attempt to use a secondary SMTP service (e.g., Mailtrap), and then a third option if necessary.

Features

• Automatic failover to secondary and tertiary SMTP services if the primary SMTP fails.
• Admin notifications of downtime for each SMTP service.
• Configurable SMTP options for up to three different SMTP services.
• Provides reliability in sending emails even during service interruptions from primary SMTP providers.

Plugin Configuration

In the plugin settings, you can configure up to three SMTP servers for email delivery:

1. Primary SMTP – Primary SMTP service (e.g., Mailgun, Mailtrap).
2. First SMTP – First SMTP service to use if the primary SMTP (e.g., Mailgun, Mailtrap) fails.
3. Second SMTP – Backup SMTP service to use if the first fails.
4. Third SMTP – A tertiary SMTP option for use if both the first and second services are unavailable.

These SMTP services can be configured in the plugin's settings as follows:

• SMTP Host
• SMTP Port
• SMTP Username
• SMTP Password
• SMTP Encryption (SSL/TLS)
• From Email Address
• From Name

How the SMTP Failover System Works

The plugin works under the following conditions to ensure emails are sent successfully even when there are issues with your primary SMTP service:

1. Primary SMTP Failure:

   • If the primary SMTP service fails (due to network issues, authentication problems, etc.), the plugin will automatically attempt to send the email using the First SMTP configuration.
   • If the first SMTP is successfully used, a downtime notification will be sent to the downtime email address user indicating that the Primary SMTP service is unavailable.

2. First SMTP Failure:

   • If the first SMTP service fails (due to network issues, authentication problems, etc.), the plugin will automatically attempt to send the email using the Second SMTP configuration.
   • If the second SMTP is successfully used, a downtime notification will be sent to the downtime email address user indicating that the First SMTP service is unavailable.

3. Secondary SMTP Failure:

   • If both the First SMTP and Second SMTP fail, the plugin will attempt to send the email using the Third SMTP configuration.
   • A downtime notification will be sent to the downtime email address user indicating that the First and Second SMTP services are unavailable.

4. All SMTP Failures:

   • If none of the configured SMTP services are functional (i.e., the first, second, and third SMTP configurations are all incorrect or unreachable), the email will not be sent.
   • In this case, no email will be delivered to the recipient, and the downtime email address will not receive further downtime notifications.

SMTP Downtime Notification to Admin

• Admin Notification on First SMTP Downtime: If the plugin detects that the First SMTP service is unavailable, the admin will receive an email notification informing them of the downtime and indicating that the second SMTP service is being used.
• Admin Notification on Second SMTP Downtime: If the First SMTP service is unavailable and the Second SMTP also fails, the downtime email address will receive another email notification informing them that both the first and second SMTP services are down, and the plugin is switching to the third SMTP service.

Best Practices

• Ensure Correct Configuration: Always double-check your SMTP settings for each configured SMTP service. Incorrect SMTP credentials or server details can result in email delivery failures.
• Monitor SMTP Services: Regularly monitor the status of the primary SMTP provider (e.g., Mailgun, Mailtrap) to identify and resolve issues before they impact email delivery.
• Update Backup SMTP Credentials: If you change or update any of your SMTP services, make sure to update the details in the plugin settings to avoid any service interruptions.

Troubleshooting

• Emails Not Being Sent:

  • Ensure that at least one SMTP service is correctly configured and operational.
  • Check if the backup SMTP services are correctly set up in the plugin settings.
  • Verify that your SMTP credentials (host, port, username, password) are accurate for each service.

• SMTP Downtime Notifications Not Received:

  • Ensure that the Downtime Email in the plugin settings is correctly configured.
  • Check the spam or junk folder in case the notification emails are being filtered.

Conclusion

The Alternate SMTP WP Plugin provides a reliable solution to ensure that your WordPress site can continue sending emails even if your primary SMTP provider experiences downtime. By configuring up to three SMTP services, you can ensure email delivery without interruption, and be notified if any of the configured services are down.