Best way to move mail from one server to another

[Robert Schetterer]

Am 04.09.2018 um 18:27 schrieb Sami Ketola:
> 
> 
>> On 4 Sep 2018, at 18.38, Robert Schetterer <rs at sys4.de> wrote:
>>
>> Sorry i migrated terrabytes of mail with imapsync and never had a
>> problem, it works as designed, also with maildir rsync did a good job,
>> what never worked as it should was dsync ,cause of bugs ,that may
>> changed now
>>
> 
> I would like to very much hear about the problems you had with dsync as we have successfully migrated tens of petabytes of mails with it successfully while preserving the UID numbers.
> Imapsync would have been totally out of question as it is absolutely crucial in those migrations to keep the UID -> MAIL pairs matching legacy server. And usually also POP3 UIDLs. If not keeping the data the servers would have literally melted under load when switching over then of thousands of users forcing them to redownload headers of even mail bodies for millions of mails.
> 
> Sami
> 
> 

I think you should know the dove buglist, i used dovecot since the beginning
and believe me dsync had a lot of problems, as i stated i hope this had
changed now. I didnt used/tested it again the last years cause i had no
big migration job to do, we ever tried to use it that days cause youre
right we would have prefer not broke pop3 stuff at migration. But it
never worked, so imapsync was the best way to go, also having courier,
cyrus migrations with format/namespace change etc.

Imapsync works as designed and migration might not be ideal at some
points but it has no real stoppers if migration is well prepared and
organized.


Best Regards
MfG Robert Schetterer

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