In fact, in the old server, the sieve folder of the user was holding a link file named dovecot.sieve which I re-created the same way on the new server, but the new server was expecting a dovecot.sieve folder instead under the sieve folder of the user.

After deleting this file, I could save the user preferences which re-created the correct dovecot.sieve sub-folder and other files has expected.

I have moved my old debian 10 server to a brand new debian 13 server and finally decided to keep all users on SOGo because of the use of the ActiveSync protocol.

I have moved all user data and sql databases and all worked fine.
I have updated users informations using sogo-tool for contacts/calendar and then for preferences.
All updated OK.

Now, if I try to save a user preference in the SOGo web page I get the error 'Service currently anavailable'.

In the SOGo logs I get:

When moving files from the old server to the new one I also copied the '/etc/sogo/sieve.cred' file.
I checked this file and it had 2 lines inside, the one with the old server information for 'sogo_sieve_master@not-exist.com:<password>' and a second line with the new 'sogo_sieve_master@not-exist.com:<password>' information.

I tried to remove the first line or second line to check wether it uses the old sieve credentials or the new one but in both cases I cannot save any user preferences.
I checked the user password in the 'iRedMail.tips' for the user and it is OK but even with this the TLS connection does not work.

Do I have to change the 'sogo_sieve_master' user password and how?
Is there something else I can check to get this working?