Exchange 2010: Inbound Messages not being delivered to mailboxes. The remote pipeline has been stopped. It was running the command 'get-message' -ResultSize '1000' -Return{ageInfo $true '+FromAddress -server 'fqdnexch' -SearchForward $true -BookmarkObject $null -BookmarkIndex '-1' -IncludedBookmark $false messages remain visable in the que, but are not delivered to users.

Inbound mail flow into your Exchange 2010 organization has stopped, outbound mail flow is still working correctly. You open Queue Viewer and notice all the inbound mail is not being forwarded to the recipients. Queue Viewer throws the following error The remote pipeline has been stopped. It was running the command 'get-message' -ResultSize '1000' -Return{ageInfo $true '+FromAddress -server 'fqdnexch' -SearchForward $true -BookmarkObject $null -BookmarkIndex '-1' -IncludedBookmark $false messages remain viable in the que, but are not delivered to users.

I open up Event Viewer and notice an error Available disk space for the database logs is extremely low. Message delivery to the database may be stopped. 

On this particular server the Transaction Logs for Exchange were written to a separate disk from the Mailbox Database itself (best practice for recovery).  The disk had 700MB's of free disk space, which you would think would be enough as transaction logs are only 1MB in size each. I extended the VMDK file that was hosting the transaction logs, and then extended it inside Windows giving an extra 3GB. This resolved the Available disk space for the database logs is extremely low. Message delivery to the database may be stopped error.

Another error then started being written to the Application log, it was Unable to initialize the Information Store service because the clocks on the client and server are skewed. This may be caused by a time change either on the client or the server, and may require a start of that computer. Verify that your domain is correctly configured and is currently online.

I used the following command to ensure the Exchange server clock was synced with the rest of Active Directory.

net time \\DC /set

I then reset the Microsoft Exchange Active Directory Topology service. The errors in the Event Log had ceased, and when I opened up the Exchange Queue Viewer mail flow had returned to normality.