Slow / hung mailbox migration (using reverse proxy)

[neonetman]

Good morning, and yet again I'm hoping someone can offer some guidance here on the problems we are having with mailbox migrations:-

 

• We are running Exchange 2016 CU12 with Office 3465 in a hybrid setup
  
• All our services run through Kemp Loadmaster which re-encrypts (this needs to stay in place)
  
• We are repeatedly getting this in the log files:- The job has been paused temporarily because the mailbox is locked. The job will attempt to continue again after 6/9/2020 10:26:31 AM.
  

 

I've set up an alternative URL that can bypass the Kemp, however not sure how to make the migrations use this instead

 

Can anyone help me out, as we are aiming to have our staff mailboxes migrated in time for Monday next week

Edited June 10, 2020 by witch

[chaplic]

To answer your question, you just create a new endpoints

 

Under the migration tab, hit the three dots, Migration endpoints and click plus, you'll figure it out from there

 

However, I am not convinced that's your root cause... Some kind of backup /snap?