Mail is not received and/or sent on Plesk for Windows Server: queue overflowed

Symptoms

• Mail is not sent from the server.

• Incoming emails do not reach mailboxes. No bounce messages are sent.

• There are no error messages in MailEnable logs (C:Program Files (x86)Mail
EnableLoggingSMTP).

• When tracking an incoming email message using MailEnable Message Route Trace Utility (Windows Start > Mail Enable > Message Tracking), it reports the following message:

  0EDA192C191E491F876A174B9DF97A9D.MAI seems to have been delivered to the postoffice connector, but there was no log entry on 9/29/2024 to indicate that it was delivered to any mailbox.

Cause

The outgoing mail queue in C:Program Files (x86)Mail EnableQueuesSMTPOutgoing and/or
C:Program Files (x86)Mail EnableQueuesSFOutgoing is too large (about 20 000 items or more). This prevents MailEnable from processing new messages.

Resolution

1. Connect to the Plesk server via RDP.

2. Open Plesk Services Monitor from Windows tray.

   Note: if it is not there, start Plesk Services Monitor from Windows Start > All Programs > Plesk.

   

3. Select MailEnable services and click Stop:

   

4. Open folder C:Program Files (x86)Mail EnableQueuesSMTPOutgoing and check the amount of files there.

   If there are a lot of items (about 20 000 or more):

   4.1. Go to upper folder C:Program Files (x86)Mail EnableQueuesSMTP.

   4.2. Rename the
Outgoing folder to Outgoing_full.

   4.3. Create a new folder with the name Outgoing.

5. Open folder C:Program Files (x86)Mail EnableQueuesSF and check the amount of messages there.

   If there are a lot of items:

   5.1. Go to previous folder C:Program Files (x86)Mail EnableQueuesSF.

   5.2. Rename the
Outgoing folder to Outgoing_full.

   5.3. Create a new folder with the name Outgoing.

6. Open Plesk Services Monitor and start all MailEnable services back.

   

   Note: To resend the deferred messages, move them from the Outgoing_full folder to the newly created Outgoing folder in groups of 1000 files and wait for them to be sent (the items will disappear from the folder).