I tried sending some messages with large attachments and now I keep getting the above error message (every 2 minutes). I went into my outbox and deleted the offending messages but I still keep getting the error message. I'm not going thru an Exchange server. I even went to my webmail from my ISP and deleted the messages from my "sent mail" box (I'm using IMAP). Still no change, every 2 minutes I get the same error message.