Have at least 3 emails that got SEND Error for size exceeding 20480 kb. Mail server still retries Send every time while sending something new. If they are in some "OUTBOX" it isn't visible to Windows LiveMail or to the Webmail.
How can we delete the oversize messages???
Not sure what you are asking.
The message is for ONE message and it should be indicated in the message. The messages being resent would be in your outbox, and it should be easy to see the approximate size.
And you are talking to peers here. NOT VERIZON. So what are you using for your eMail client. I assume not Webmail as it should catch it before you send it.