I would use Thunderbird myself. Here's how to create a debug log for it:
[This is from
Debugging/Thunderbird - Dovecot Wiki]
Debugging using Thunderbird's logging
Thunderbird has the ability to log its client actions based on protocol; this can be useful when you're experiencing a problem with Dovecot and want to trap the commands that the client is sending.
Windows batch file
Save the below as runtbird.bat and place it on the desktop, then run this instead of the Thunderbird icon.
set mydate=%date:~-4,4%%date:~-7,2%%date:~-10,2%
set mytime=%time:~0,2%%time:~+3,2%
set NSPR_LOG_MODULES=IMAP:5
set NSPR_LOG_FILE=%USERPROFILE%\thunderbird_%mydate%_%mytime%.log
start /d "c:\program files\mozilla thunderbird" thunderbird.exe
Adjust the log location and Thunderbird install folder as appropriate. If you want to log all modules instead of just IMAP (SMTP, e.g.) then replace "IMAP" above with "all". The above will create a date/time stamped logfile for each run, so you won't lose the previous logs.
The info logged is pretty detailed and it might not be particularly useful to someone who is not well-versed in IMAP. But at least the data is there for what it's worth.