we use a non-profit portal (“coopamde”) and I was redirected here by the support team:
One of our users can still log in and access/edit documents, but has no access to emails and when we sent mails to her, we receive back an error message saying :“user@organisation: user unknown” !
Sorry, I realize that there was no question, here it is: I don’t see anything we, user, can do, could an OnlyOffice tech look into it?
Hello @loic.jaouen
If you have admin access to the portal, please check if their email exist in Mail module > Settings > Account Management.
Can you share a screenshot?
By the way, did the user activated the account?
Hello @Constantine , the most probable hypothesis is that another admin deleted accidentally the mal account.
Sorry for the noise, the mistake might be only on our side.
For our defense, it is easy to delete a mailbox instead of removing it from a mail group.
On the mail groups management page:
“Mail > Settings > Mail server”
For each group there is a line with the users’ mail boxes.
So one user who is in two groups has two lines.
At the end of the line there is a drop down list for action, and one that says “delete mailbox”.
Which deletes the mailbox (as it rightly says 
) when one could expect it to delete it from this group, as the context might suggest.
Thanks again for answering, best regards,
Loïc.