Dodo wrote:

What is Outlook sending when I press send/receive button?
It says that it is sending between 5 & 7 items. There is nothing in
the outbox.
This can happen even if I have done nothing in Outlook for quite some
time (2 hours).
All read receipts have been processed

Still, check for undeliverable read receipts.
http://www.howto-outlook.com/howto/d...eadreceipt.htm
--
Brian Tillman [MVP-Outlook]