Disabling SSL and TLS for Message Relaying

Outgoing SMTP connections time out while sending e-mails to some domains.

Issue cause

Some email servers advertise support for some SMTP features that they cannot handle. This is very likely with content control gateways.

Solution

A custom Acceptance & Routing advanced rule must be defined from the webadmin interface.

To do this, log into the webmail interface and go to "Security & Filtering" -> "Acceptance & Routing" -> "Advanced Settings" tab. On the page that loads, click the "Add acceptance / Routing rule" button.

Set the name of the custom rule to something suggestive, like "Relay-Timeout". In the "Conditions" section, leave the settings as they are, for the rule to match any e-mail message. In the "Actions" section, select from the drop-down box "SSL encryption" in the "Relay" section. Click the "Add action" button. From the same drop-down box, select "Settings" -> "Allow Start TLS" and click the "Add action" button again.

You must make sure that both of the checkboxes for the added actions are un-selected for this workaround to achieve its goal. Click the "Save configuration" button at the bottom of the page to save the rule and enable it.
OS: LinuxWindowsFreeBSDNetBSDOpenBSDSolaris
Distros: WindowsDEB based distros amd64