ManagedAvailability problem with Mailbox Transport Submission after CU6

Question

We are getting the following error after CU6 implementation:
Seems like a latency issue... But, all tests are succesful, we are not experience any harm/issue. So, can we consider it as "by design" or should we take action?
Mailbox Transport Submission - the verification that the probe messages were successfully submitted within 5 minutes to HUB has failed.
This could indicate that the mailbox submissions are taking too long or not progressing at all.
SequenceNumber: 635484312145508431
Error: MapiSubmitLAMProbe finished with CheckPreviousMail failure.
FailureContext: MapiSubmitLAMProbe finished with CheckPreviousMail failure.
ExecutionContext: MapiSubmitLAMProbe started. This performs - 1. Submits a new message to Store 2. Checks results from previous Send Mail operation. Sequence # = 635484312145508431. First Run? = False. Previous mail submission to store was successful. Results
- # of previous results: 0. Could Not Find stages that ran. Previous SendMail failure - Mail submitted to Store during the previous run never reached SendAsCheck.
This may indicate a latency from Store to Submission Service. Investigating. Found lower SA latency. Indicates an issue in Submission service.

Answer 1

Using the message tracking logs, i found that my single exchange server tries to be high available and therefore wants to copy the mail to be transported to a different server before it transports it.As it can not find a suitable server to backup to, *THIS
BACKUP ONLY STEP* failes. The transport will be done nevertheless, without problems.
Get-MessageTrackingLog -Server MyServer -messageid [email protected] | ft Timestamp, EventID
Timestamp EventId
11.04.2015 01:51:36 DELIVER
11.04.2015 01:51:36 RECEIVE
11.04.2015 01:51:36 SUBMIT
11.04.2015 01:51:36 --> HAREDIRECTFAIL <--
11.04.2015 01:51:36 RECEIVE
11.04.2015 01:51:36 AGENTINFO
11.04.2015 01:51:36 SEND