Mail.que file keeps growing in exchange 2013.

Question

We have identified that mail.que file is rapidly growing that is eating up our disk D: storage. As per checking the SafetyNetHoldTime we have found out that it is in default value (2 days)

I moved the mail.que file from disk D: to E: and used the command prompt to create a new queue database and transaction logs in a new location from D:\Microsoft to E:\Queue\QueueDB. I have Verified that the new database files Mail.que and Trn.chk exist at the new location.

The moving of mail.que to another location is a success but we have monitored that the mail.que file in the E:\Queue\QueueDB is still growing rapidly. Please see details below for our monitoring summary of mail.que file in E:\Queue\QueueDB.

After 2 hours: 13GB
After 6 hours: 29GB
After 20 hours: 87GB
After 23 hours: 95GB

The question is, is this still normal even after all the activities that we have executed above the mail.que file is still growing rapidly.

Answer 1

Yes, you can delete it if there is no pending mail following that link:
https://techcommunity.microsoft.com/t5/exchange-team-blog/transport-database-understand-size-and-troubleshoot/ba-p/1113388

No, not related to circular logging, since that is about truncating the logs.

Answer 2

Is it still growing? It should stabilize after a day.
If not, then you have an excessive mail loop or are sending an enormous amount of mail.
Also ensure that no flat file anti-malware scanning is happening on the Exch directories
Are there any 3rd party add-ins installed on the server?
When did this start being an issue?

Answer 3

I wouldnt deleteit if you have pending messages
You can follow this to recreate it and troubleshoot:

https://techcommunity.microsoft.com/t5/exchange-team-blog/transport-database-understand-size-and-troubleshoot/ba-p/1113388

Message tracking may show any excessive mail loops.

I would disable AV yes and test.

When did this start?