I've been using windows live mail 2011 successfully for a long time for my gmail account ( set up by wizard so uses IMAP folders).  I have no other email accounts. Suddenly , during a session , my sent mail was no longer appearing in my 'Sent Mail' folder. I suspect some local file corruption. If I send messages using the gmail webmail the messages DO appear in the local 'Sent Mail'  folder so IMAP synchronisation is working OK. The sent messages were still appearing in the local All Mail folder and I can move them OK to 'Sent Mail'. and get them synchronised)

I tried reading all relevant 'answers' to similar problems.

I moved all sent messages from 'Sent Mail' to a subfolder in 'All Mail' in order to empty the 'Sent Mail' and used 'properties' to click DELETE all messages and headers. This did not work.

I removed the gmail account from live mail , and set it up again ( using the wizard).

I have used from control panel the 'repair windows live essentials'.

I've unset and reset the box for 'save copy of sent messages in the 'sent items'. And rebooted lots of times. I've reviewed all likely settings and they are unchanged. I've reset the IMAP folder list.

I'm hoping there is a simple remedy as I've now spent many hours 'experimenting' with no success.