Email on Pantheon

Detailed information on outgoing mail and email hosting for your Pantheon Drupal or WordPress site.


Incoming Email

Pantheon does not host inboxes for incoming mail. We recommend using an externally hosted email solution, such as Gmail.

Outgoing Email

For outgoing emails, we recommend integrating a third-party service provider that supports a REST API configuration. You can use an SMTP configuration, but because SMTP requests are associated with dynamic outgoing IPs there can be negative impacts to deliverability. For a detailed comparison between API configurations and SMTP, see this related blog post from SendGrid.

REST API Providers

Here are some popular email services you can use on the platform and their corresponding Drupal or WordPress integration method:

Provider Integration
SendGrid Drupal | WordPress
Mandrill Drupal | WordPress
Mailgun Drupal | WordPress
SparkPost Drupal | WordPress

SendGrid, a high-deliverability email service, offers several plans to meet your specific needs. For more information, see Using SendGrid To Deliver Email.

SMTP Providers & Configurations

Customers have successfully used SendGrid, Gmail, Amazon SES, Mandrill, and other externally hosted SMTP based email providers.

Configuring mail to use port 25, 465 or 587 is strongly discouraged because they attract SPAM activities. Here’s a list of popular email providers and the alternate ports which Pantheon recommends:

Provider Port Documentation
SendGrid 2525
Mandrill 2525
Mailgun 2525
SparkPost 2525
Amazon SES 2587 (STARTLS), 2465 (TLSWRAPPER)

If you do not find your service provider in the table above, check with their support and/or documentation.

Use the following integration methods for Drupal and WordPress to configure an external SMTP service:

Once you have chosen your SMTP provider, install and configure Drupal's SMTP Authentication Support module.
Once you have chosen your SMTP provider, install and configure Wordpress's WP Mail SMTP plugin.

Troubleshooting

Failed Opening MimeMailSystem__SmtpMailSystem.mail.inc or HTMLMailSystem__SmtpMailSystem.mail.inc

This is a common error with the SMTP Authentication Support module. It can be fixed in a few steps:

  1. Copy the file from .../files/mailsystem/filename.inc
  2. Place in a custom module's includes dir and .info file using files[] = includes/filename.inc.
  3. Remove the original file from the {registry} table:

    DELETE FROM registry WHERE name='[appropriate-name]' AND module='mailsystem';
    
  4. Clear the cache:

    terminus drush <site>.<env> -- cc all
    

See available patch.

Unable to Send Mail with Amazon SES

SES places new users into 'sandbox mode' to help prevent fraud and abuse. If you are having trouble sending mail and are using SES, confirm you are not in sandbox mode. For more information, see AWS documentation on sandbox mode.

Frequently Asked Questions

Can I use Pantheon's local MTA (postfix)?

We strongly recommend that you do not use the local MTA (postfix) as described above. Instead, we recommend using a third-party email service provider.

Can I access the mail logs for my site?

No, mail logs are not available for download and we do not recommend using the local MTA (postfix).

Configuring mail to use port 25, 465 or 587 is strongly discouraged because they attract SPAM activities. Make sure that your service provider allows traffic on a port other than those mentioned and that you have correctly configured your site to use that port.

Can Pantheon provide, publish, or support SPF records?

As consumers of cloud infrastructure, we don’t have control over our IP ranges and they are subject to change without our notice. Publishing an SPF record would imply assurance on our end that it can work, which would be very difficult to guarantee given these circumstances. We take the decision of what we support and what we don’t very seriously, and at this time we’re not in a position to support SPF records.

Why does my Gmail user name and password not work?

Please see Google's help article: My client isn't accepting my username and password.

Can I use Microsoft Exchange or Office 365 for my emails?

Offce 365 uses ports 25 and 587 by default, and different options for sending via SMTP client, Direct send or SMTP relay. This document outlines the limitations and configurations of each, to know what will work for your application.

Because we don't support SPF, it is likely that most Exchange or Office 365 servers won't work if its configured at your email server. Check your organization's Microsoft Exchange settings on what's allowed by your system.