[Dovecot] Differences between IDLE when Maildir vs. wel the "mail" folder is used

[Philip Van Hoof]

Are there any differences with how both IDLE and "UID FETCH n:n+x (FLAGS
UID...)" are handled when Dovecot is using a "mail" vs. a "Maildir"
user?

I have recently implemented support for IDLE (Push E-mail) in a client
infrastructure that I'm building. I haven't in depth checked out what
the problem might be, but when Dovecot was using the "mail" dir in $HOME
something about the implementation wasn't working. When I switched to
"Maildir" everything worked. 

I only tested to the point of seeing the "* EXISTS n" response during
the idle. I saw this response. It's for example possible that the n is
wrong or that a bit later the "UID FETCH ..." ain't returning the right
information. It's also possible that my implementation is wrong (of
course) and I haven't yet had the time to really figure out what goes
wrong.

I did so far, however, test with Cyrus, Exchange, Courier and Isode's
M-Box. All these tests where successful. SO if it indeed is a
discrepancy in my implementation .. it's going to be something very
specialised or specific I fear :-)

I also setup testing infrastructure 
http://tinymail.org/trac/tinymail/wiki/TestImapServers


Also take a careful look at this manual test. "tnytest" is a user on
imap2.tinymail.org that uses Maildir. The "tnytest2" user doesn't have a
Maildir configured. By that I mean that "Dovecot" has created the folder
for E-mail using whatever it uses by default.

Dovecot's IDLE (the EXISTS) responses also take a lot longer on tnytest2
than on tnytest.

Another question. Why not simply "always" use the Maildir solution if
that one works better? ;-) (really, honest question. Hehe).

Take a look at the "UID FETCH" response: It's incorrect on tnytest2. The
first attempt I asked for 1:1 and I got none. The second I asked for 1:4
and I got 3 of them, while IDLE clearly stated that there where 4
messages available. In reality 4 where indeed available (or copied in
total).

Well, I'm not saying something is or isn't wrong, just wondering and
testing a little bit and seeing some strange results...

Feel free to use imap2.tinymail.org for testing. And if you need root on
that virtual machine, so that you can install a new version, go ahead.
On http://imap2.tinymail.org you van find things like version
information (it's a CVS snapshot).


pvanhoof at lort:~$ telnet imap2.tinymail.org
Trying 86.39.154.77...
telnet: Unable to connect to remote host: Connection refused
pvanhoof at lort:~$ telnet imap2.tinymail.org 143
Trying 86.39.154.77...
Connected to imap2.tinymail.org.
Escape character is '^]'.
* OK Dovecot ready.
ao1 login tnytest tnytest
ao1 OK Logged in.
a01 select INBOX
* FLAGS (\Answered \Flagged \Deleted \Seen \Draft)
* OK [PERMANENTFLAGS (\Answered \Flagged \Deleted \Seen \Draft \*)]
Flags permitted.
* 1 EXISTS
* 0 RECENT
* OK [UIDVALIDITY 1171049606] UIDs valid
* OK [UIDNEXT 2] Predicted next UID
a01 OK [READ-WRITE] Select completed.
a04 IDLE
+ idling
* 2 EXISTS
DONE
a04 OK Idle completed.
UID FETCH 1:2 (FLAGS UID)
* 1 FETCH (FLAGS (\Seen) UID 1)
* 2 FETCH (FLAGS (\Seen) UID 2)
UID OK Fetch completed.
^]

telnet> quit
Connection closed.
pvanhoof at lort:~$ telnet imap2.tinymail.org 143
Trying 86.39.154.77...
Connected to imap2.tinymail.org.
Escape character is '^]'.
* OK Dovecot ready.
a01 login tnytest2 tnytest
a01 OK Logged in.
a01 select INBOX
* FLAGS (\Answered \Flagged \Deleted \Seen \Draft)
* OK [PERMANENTFLAGS (\Answered \Flagged \Deleted \Seen \Draft \*)]
Flags permitted.
* 0 EXISTS
* 0 RECENT
* OK [UIDVALIDITY 1171107413] UIDs valid
* OK [UIDNEXT 1] Predicted next UID
a01 OK [READ-WRITE] Select completed.
a04 IDLE
+ idling
* 1 EXISTS
DONE
a04 OK Idle completed.
a05 UID FETCH 1:1 (FLAGS UID)
a05 OK Fetch completed.
a04 IDLE
+ idling
* 4 EXISTS
DONE
a04 OK Idle completed.
a06 UID FETCH 1:4 (FLAGS UID)
* 1 FETCH (FLAGS (\Seen) UID 2)
* 2 FETCH (FLAGS (\Seen) UID 3)
* 3 FETCH (FLAGS (\Seen) UID 4)
a06 OK Fetch completed.


-- 
Philip Van Hoof, software developer
home: me at pvanhoof dot be 
gnome: pvanhoof at gnome dot org 
http://www.pvanhoof.be/blog