11.12.2. Configuring Email Ports

OpenShift Online provides support for externally hosted email services, such as POP, IMAP, and SMTP. An application can be connected to your own email server, or to one of the popular public email services, such as Gmail or YahooMail. With support for popular blogging or wiki software, such as Drupal, Joomla, MediaWiki, or WordPress, email settings of the software can be modified to point to the appropriate email service.
The following ports are the suggested options for email support:
  • SMTP/submission: 25, 465, 587
  • IMAP: 143, 220, 993
  • POP: 109, 110, 995
Communication occurs at a limited rate. Port 587 (submission) is restricted to a maximum rate of 256 Kbps. Ports 25 (SMTP) and 465 (SMTPS) are restricted to a maximum rate of 24 Kbps. Both consume an extremely small share of the available bandwidth if there is congestion.

Important

Note that access to email servers from cloud providers may be blocked by Realtime Blackhole Lists (RBLs), affecting connections to some email servers. If you are unable to connect to one of these services, ensure the email provider allows authenticated connections from Amazon AWS EC2 hosts.