A couple times recently I sent an email from my .mac account, from my iMac, and received this response: - - - This is an automatically generated Delivery Status Notification. Delivery to the following recipients failed. ******firstname.lastname@example.org Reporting-MTA: dns;COL0-MC2-F8.Col0.hotmail.com Received-From-MTA: dns;cdptpa-imtalb.mail.rr.com Arrival-Date: Mon, 28 Jan 2013 22:57:19 -0800 Final-Recipient: rfc822;email@example.com Action: failed Status: 5.2.2 Diagnostic-Code: smtp;552 5.2.2 This message is larger than the current system limit or the recipient's mailbox is full. Create a shorter message body or remove attachments and try sending it again. - - - THE PROBLEM is, I didn't send any email to that recipient, never ever. So I reply to 'firstname.lastname@example.org' and of course it gets kicked back to me, but with this message: email@example.com is an unmonitored account. If you need assistance, please consult our help pages or visit http://postmaster.live.com. Thank You, Windows Live Hotmail Staff - - - Any ideas on what is going on? I don't feel like emailing firstname.lastname@example.org as I have no idea who they are, but think it's strange that it is possibly trying to send an email I sent, to someone else, to this strange email address.