Yesterday afternoon I sent an e-mail with some attachments from my gmail account to a friend's hotmail account.Today I noticed an e-mail in Spam section of my account with a title "Delivery Status Notification (Failure)". The e-mail says the delivery to my friend's account failed as either the size my mail was too big or her account was full. There seems to be only a couple of minutes between my sending of the e-mail and the latter being generated.And it has my friend's address correct.There seems to be nothing dodgy about it. So why did it end up in Spam section?My gmail account's spam filter is set at default level. I rarely check my Spam section so I'd like to be notified if my e-mail bounces.At the same time if it is a spam,I obviously don't want to add firstname.lastname@example.org to my safe list. Can someone help? Thanks in advance.