You can disable that specific service using the windows service controller. Once disabled there, ME will not be able to start it.

This seems to have been fixed in release 10.49

We support around 5K mailboxes with 3 load balanced servers using regular spindle drives in a RAID-10 over SMB share for both config and Postoffice storage. We also use a MSSQL database for the system. Have not experienced any slowdowns under normal traffic and typically have at least 300-400 users ...

Seems to be resolved in the 10.49 release. SMTP service has not crashed since the update and DKIM signing is working normally.

It's looking like the 10.49 release did actually resolve the issue. will post here again if it comes back

Installed the new version 10.49 published today hoping it would resolve the issue. No such luck... Including another entry found in the debug log

08/26/24 16:55:27 Service_DumpConnectionsToFile raised an exception.
The exception occurred in : ..\SERVICES\Library\LIBappStatus.cpp, line 341

Disabled DKIM for all domains and for now at least the issue seems to be cleared...

Only change to the systems are the recent August updates from Microsoft although they were installed a few days before the issue started.

Found this same subject over in the professional version forum Suddenly getting errors and SMTP service crash issue related to DKIM signing. Have tried excluding the entire Mail Enable folder from AV scanning Including relevant errors from the smtp debug log 08/22/24 13:14:59 Service_DumpConnections...

This same issue started popping up our servers yesterday. SMTP service seems to keep crashing with errors related to DKIM signing The exception occurred in : SMTPOutbound.cpp, line 4389 08/22/24 13:04:18 DKIM_SignMessage raised an exception. The exception occurred in : SMTPOutbound.cpp, line 4389 08...

It seems that only a sysadmin level user can edit postoffice filters in the web admin.

Am I missing something in config?

Have only seen this issue when the user allows their inbox to get a crazy large number (>50K) of messages. have them delete the account from Outlook, readd it and then do some cleanup.

Depending on how you have the services configured, you might check to see if "everyone" can read the private key. Have had that issue with services that are set to run with a user's permissions.

If your domain is on the new server you could just delete your domain from the old server's postoffice our you could allow relay for the new servers IP on the old server

that file should already be gone. It goes away once the folder refresh is done.