saslauthd and "plus addressing"

[Anders Norrbring]

I'm trying to make my POP3 users authenticate to the mail server. It's 
running saslauthd for POP3 access, and it works just fine.
However, I would like to enable the use of "pop from subfolder", which 
would demand a user to login with "username+folder", and of course 
saslauthd doesn't allow that.

When doing a local telnet session, this shows:

Connected to localhost.
Escape character is '^]'.
+OK iris Cyrus POP3 v2.1.15 server ready <3897138353.1157646393 at iris>
user nb0003+folder
+OK Name is a valid mailbox
pass <not shown>
-ERR [AUTH] Invalid login

user nb0003
+OK Name is a valid mailbox
pass <not shown>
+OK Maildrop locked and ready

So, the Cyrus POP daemon correctly finds the mailbox, but saslauthd 
cannot verify the user.  Is there a way to recofigure it so it'll work?

-- 

Anders Norrbring
Norrbring Consulting