Dovecot "User-Agent" equivalent

Hi,

I was trying to debug an IMAP connection problem. The client accesses an account via webmail, mobile phone, and desktop. I was wondering if there was a way of determining which of these they were using at a given time.

My googling turned up the following settings in the imap{} section:

protocol imap { imap_id_log = * imap_id_send = "name" * "version" * }

... but setting these didn't seem to log any more information that I could use.

Have I misunderstood the usage of these settings? Shouldn't they log a "user agent" type information in /var/log/dovecot.log ?

Or are there any other ways I can get information on the client?

P.