IMAP Migration to G Suite

[limbskars94]

Hi, For various reasons we are currently working to migrate circa 1,400 users of our self hosted Zimbra Collaboration Server (8.5) to Google G Suite.

I have been attempting to run a migration for some time now using the IMAP Migration Tool provided by Google but it consistently fails after a period of time. There is nothing really telling in the Zimbra logs regarding the migration, I can see the IMAP Socket get opened, the migration in progress then shortly after the migration fails the socket is reportedly gracefully closed by Zimbra.

I have been searching but not been able to turn up anything, is there some kind of IMAP Timeout on the Zimbra Side that might be causing this migration to fail?

Really looking for any suggestions or solutions at the moment so I can wrap this project up and move forward, any help would be most appreciated!!192.168.0.1 routerlogin 192.168.l.l