Answer

PROBLEM

When GFI MailEssentials is enabled, emails are building up in the SMTP queues. No emails sent in or out.

• There are no obvious errors in the logs
• Autowhitelist has hundreds of thousands of entries

ENVIRONMENT

• GFI MailEssentials
• All supported environments

SOLUTION

Delete all Autowhitelist entries, leaving a maximum 100,000, directly from the autowhitelist.mdb or Controlists.sdf. Set the maximum entries in the autowhitelist module to 100,000.

CAUSE

The Autowhitelist has too many entries which can't be loaded by the MTA. There is no hard coded limit, but the amount of time it takes to process these entries bypasses most timeouts for service responses.