[Dovecot] restrictions on folder length?

[Brett Dikeman]

Greetings all,

After migrating a few dozen people to our departmental mailserver,
we've run into a problem with one user who makes extensive use of
folders and nesting them.  I've seen as many as 8 levels.  The longest
resulting folder name is 113 characters, which results in a total path
length of 137 characters (/var/spool/mail/******).

Their old mail server handled this fine, but dovecot is choking on it;
imapsync reports "invalid mailbox name", and he gets the same error
clicking on the mailboxes in Thunderbird (they seem to have been
created, despite the error messages.)

Mail was imported over using imapsync, and did so flawlessly for all
the other accounts.

Are we running up against a soft (configuration file) or hard (source)
limit?  Or is this a bug?

Thanks!
Brett