I keep trying to send several emails with attachments but it keeps failing. I did send a couple of them until it just stopped allowing me to.

Basically, the attachments are uploaded and the email is "sent", but it the browser goes directly to my SENT folder where there are no signs of those send emails. When I add my email address to the recipients, I receive a DELIVERY STATUS NOTIFICATION email...

It also doesn't work sending the email with attachments from my smartphone.

Help?