[Dovecot] tags disappear in Thunderbird (OT: Maildir preference)

[Jakob Curdes]

> Could I offer our reasoning for choosing Maildir?
>
> I made the decision that we would use Maildir because I was worried 
> about the effect of loss of a single file.  As I understood it, mbox 
> stores all the messages in single file and, if the file was corrupted 
> and couldn't be recovered for any reason, then we'd lost a whole lot 
> of messages.
I do not agree to this view; there are two possible scenarios what could 
happen:

a) filesystem corruption - with maildir you probably end up with an ugly 
mess of unconnected directories, while for mbox you need to find the one 
file (per folder) for user x.

b) file is corrupt (altered by two processes, bad sector, filesystem 
corruption on file level) - the mbox file can be repaired easily, if you 
want, by hand.
For maildir you need to find the affected parts of the directory 
structure, probably more than one file will be affected as dovecot needs 
to open many nodes simultaneously

In all these cases it is best to have a current backup (which is easy to 
say but hard to achieve with classical backup methods for a mail 
folder). In either case you could spend hours on fitting pieces together 
and even then you are not sure that nothing is missing.

That said, we use maildir and mbox formats for several hundred 
mailaccounts in different setups and never had a real corruption 
problem, besides one issue with badly formatted From: lines several 
years ago.

Jakob Curdes