Hello Nikola, 

We do not have anything in place to support this. You best bet will be to do an IMAP migration of the users from one version to the others. 

Thank you

I am editing this post. I NO LONGER recommend EDBMails. It does NOT perform as well as it did when I originally began using it, and I'm not sure why.

Do yourself a favor and use something else, such as TranSend migrator. 

Again, I left the following in place, but my recommendation for EDBMails has changed to NOT RECOMMENDED.

edbmails.com has a well supported Windows program for IMAP (and other kinds of) email migration. Bit of a learning curve BUT they have 24x7 LIVE web chat support with screenshare if needed. Program is updated often, and very reasonable per user. I have recently used the program extensively for IMAP to Microsoft 365 migrations, and some IMAP to IMAP as needed. Works very well. Full and (repeated if necessary) incremental migrations are supported, no additional charges when re-migrating the same user account.

I looked at BitTItan, Transend, and others, and this one was the best supported, with friendly pricing as well.

I have no financial interest in edbmails. And as usual, YMMV.

I'm not sure if you guys know this, but IMAPSync offers a free, online version of their program which is super easy to use. It only supports transfer of mailboxes up to 3GB, so if your mailboxes are smaller this is a nice choice in my opinion. I have used it several times for smaller projects with no issues. Also, I have used Bittitan's MigrationWiz for larger projects and it works very well too.

Yes, we use IMAPSync for some stuff, and it is a great tool, but it would be better/easier to have native SM support. That way we could copy all the settings from one server to another, not just e-mail content.
Also, thanks for your suggestion Zack, but migrating mailboxes individually is not an option, since we have domains with large number of accounts.

Regards

It is very easy to migrate an entire SM installation from one server to another. Is that what you mean? Or do you mean that you would want a tool that migrated just users from SM to another mail server (mail, contacts, calendars, notes etc..)?

Moving from SM to SM is very easy either way. You can move your entire installation or per domain/user.

As for moving from SM another mail server software, I agree, a tool would be nice, but I think that would be the responsibility of the mail server software you are moving to and not SmarterTools.

There were some 3rd party utilities that helped with moving TO SmarterMail. I remember there was one for Imail to SM, Merick to SM and a few others. They may still be available somewhere, but the Imail one no longer works :)