Is IMAP IDLE incompatible with preauthtunnel = ssh ?

[Eygene Ryabinkin]

Marc, good day.

Tue, Sep 17, 2013 at 08:28:08AM -0700, Marc MERLIN wrote:
> When I connect to my courier server over imap/ssl, IDLE works:
>  DEBUG[imap]:   14:16.40 Account sync merlins.org _get_untagged_response(CAPABILITY) => ['IMAP4rev1 UIDPLUS CHILDREN NAMESPACE THREAD=ORDEREDSUBJECT THREAD=REFERENCES SORT QUOTA IDLE AUTH=PLAIN ACL ACL2=UNION']

And it is even advertized from the IMAP server -- that's good.

> But if I use 
> preauthtunnel = ssh -x -q imap '/usr/bin/imapd ./Maildir'
> it works fine, except for IDLE:
> 
>  Establishing connection to tunnel:ssh -x -q imap '/usr/bin/imapd ./Maildir'
> INFO: LOGIN, user=merlin, ip=[127.0.0.1], port=[0], protocol=IMAP
> Folder INBOX [acc: merlins.org]:
>  Syncing INBOX: IMAP -> Maildir
> Account sync merlins.org:
>  *** Finished account 'merlins.org' in 0:03
>  Next refresh in 30.0 minutes
> Thread-4:
>  WARNING: IMAP IDLE not supported on server 'ssh -x -q imap '/usr/bin/imapd ./Maildir' '.Sleep until next refresh cycle.

This message is given when IMAP server isn't advertising IDLE support
in response to the CAPABILITY, so I wonder what IMAP debug gives you
on that response in the SSH-based mode?

I fear that your Courier is configured to avoid IDLE stuff when
working over SSH and invoking imapd by hand.  Usually, it is
IMAP_CAPABILITY configuration setting for Courier IMAP that governs
the support for IDLE, see
  http://www.courier-mta.org/imapd.html
-- 
rea