Hello everybody,
we are running exchange 2013 with cu1 wit 2 CAS (ex01 and ex02) and two MBX-Servers (ex03 and ex04). We are already in a call there with Microsoft. Anyway i'd like to describe the existing Problem here.
We have 4 Databases productive, that only deliver mail (any mails, with/without attachments) when being mounted on ex03.
As soon as they are mounted on ex04 mails with attachments from the outside and from the inside are not being delivered to users Mailboxes and stay in the queue with a '452 4.3.1 Insufficient system ressources' All disks have enough free space, no corresponding eventlog showing a problem because of throtteling. Mails without attachments run just fine.
In the message-tracking Log we see a 'recipientthreadlimitexceeded, intra-organization SMTP Send Connector'. With MS-Support, we tweaked the msexchangedelivery.exe.config with different values for
<add key="RecipientThreadLimit" value="20"/>
<add key="MaxMailboxDeliveryPerMDBConnections" value="60"/>
<add key="MailboxServerThreadLimit" value="240"/>
and Edgetransport.exe.config with
<add key="RecipientThreadLimit" value="7"/>
<add key="MaxMailboxDeliveryPerMDBConnections" value="8"/>
This did not resolve the issue.
We disabled the Anti-Malware-Agent in the Transport. There is Mcafee on the system (as is on the others) with proper exclusions (the others run just fine with that config)
We set tnef to false. I don't know if this caused the issue on the system, setting it back to true did not resolve the issue.
We have all the productive db's now running on ex03. When adding a new DB 'test' on ex04 and putting one test-mailbox on thar db we are able to reproduce the problem without Userimpact.
Well, anyone has an Idea? As i said, MS is right now analysing a trace. I'll keep this thread updated.
Regards
Michael