Ensuring email deliverability on Pantheon
From Pantheon's Platform Considerations:
"Because of the cloud-based nature of Pantheon's infrastructure, we cannot ensure high-deliverability email originating from your Application Containers, as they have no fixed location. While all sites have access to a local Postfix service for testing and development, we recommend using an external SMTP gateway (SendGrid, for example) in production to ensure that your email is delivered".
The best way to set this up is using authenticated SMTP via the campus authenticated mail relay server (authenticated.relay.mail.utexas.edu
), using the appropriate Wordpress/Drupal plugin to send the application's mail to this external server.
Step 1: Request a Service EID
Follow the request form instructions at https://ut.service-now.com/sp?id=kb_article&number=KB0019435
You will need to provide:
- A department code
- Service name
- EIDs of two technical contacts
In your request, indicate that this Service EID will be used for authenticating to the campus mail relay server.
Step 2: Whitelist Service EID
Send an email to postmaster@utexas.edu with the following text, replacing "<EID>" with the actual Service EID username:
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Please grant service EID, <EID>, rights to use authenticated.relay.mail.utexas.edu. This is for <SITE_URL>, which is a website hosted on Pantheon.
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Step 3: Configure website to use external SMTP gateway.
Drupal Configuration
Pantheon recommends using the SMTP Authentication Support Module. After enabling the module, enter the following as a new "provider" at /admin/config/system/smtp
Server | authenticated.relay.mail.utexas.edu |
Backup server | N/A |
Username | Service EID |
Password | Service EID password |
SMTP Port | 25 |
Use encrypted | Yes (TLS only, no SSL) |
WordPress Configuration
Pantheon recommends using the WP Mail SMTP plugin. After activating the plugin, set the following values in Settings -> WP Mail SMTP and save.
Mailer | Other SMTP |
SMTP Host | authenticated.relay.mail.utexas.edu |
SMTP Port | 25 |
Encryption | TLS |
Authentication | On |
SMTP Username | Service EID |
SMTP Password | Service EID password |