Symptoms

Not Receiving the Email from k2
 

Diagnoses

A cross check between Process Audit Data & ClientRecorder table reveal this error thrown from MSMQ:-
"System.Messaging.MessageQueueException (0x80004005): Insufficient resources to perform operation"

Resolution

We have spent some times trying to pinpoint the cause of this error and tried various measures to tackle this resources error. From the call with customer, we realize that this is a very misleading error as this has nothing to do with the resources but it's due to size limit imposed by MSMQ (4MB):-
http://blogs.msdn.com/b/johnbreakwell/archive/2007/08/22/why-is-there-a-4mb-limit-on-msmq-messages.aspx

This was logged as enhancement request to remove dependencies on MSMQ. Moving forward, there are 2 approaches to fix this permanently:-
1) Send attachments in Email Event instead, or
2) Add a link in notification for your users to access the attachments in your server instead of attach the files to the notification.