We have to migrate 5 mailboxes between 30 and 70GB from the current local postfix server (IMAP) to a second local exchange server.
> office professional 2016 that includes the outlook with which you are planning to use exchange.
> thunderbird with which imap is used.
We've seen that online and office 365 exchanges have native tools for this purpose, but we DO NOT have these licenses and given the investment just completed to purchase licenses at the premises, there's no intention of acquiring them.
Yesterday we failed ruinously in the migration in fact:
> We have configured imap accounts on outlook
> We set outlook to pull down all the mail
> We've generated PSTs
> We imported PSTs
The result was ruinous with inconsistencies in folders, missing emails etc ... In addition, in the absence of log files, progress bars etc this system does not control any.
In test, however, everything was fine.
What is the best alternative to complete migration?