I keep finding myself in a corner with a user. He uses mail extensively, which is fine, he has a huge archive of own professional correspondence, which is fine, but he uses mail folders as if they were regular system folders, with very long paths, and keeps renaming them and moving them around, daily, breaking the mail index
Hi Rupert,
I share your frustration. I have had similar users, who used mailbox as a sort of task/ticket manager. Each task was a separate folder, (with all related emails), and they renamed/moved the folder when the task status has changed.
It was OK as long as they used POP3 + Outlook and everything was in local PST folder. Until the PST grew over some limit (4 GB or such) that outlook was not able to handle.
So we migrated them to IMAP (cyrus), and ran into a problem with forbidden characters in folder names. Most prominent was "." - used for date format. But they kept on trying other special chars, always hitting something forbidden. (too late I realized I should have switched the folder separator from . to / before moving from POP3 to IMAP)
To make things worse, Outlook did not complain about forbidden characters, it just made folder "local only" and stopped syncing it to the IMAP server. Users gladly edited the folder name and removed the "local only" from the name so it was impossible to trace back which folders were synced and which not.
It was a constant pain ... Finally resolved by migrating them to MS-365. Maybe dovecot would be more forgiving, but we did not dare to try.
-- Best regards Vladislav Kurz