It happened to me yesterday.
Someone claimed she sent me an e-mail, but I did not get it.
It's not in Inbox, Spam, Trash, etc.. it's nowhere.
How is this possible (assuming there is no user error)?
Where can things go wrong?
Super User is a question and answer site for computer enthusiasts and power users. It only takes a minute to sign up.
Sign up to join this communityIt happened to me yesterday.
Someone claimed she sent me an e-mail, but I did not get it.
It's not in Inbox, Spam, Trash, etc.. it's nowhere.
How is this possible (assuming there is no user error)?
Where can things go wrong?
Tracing the path from the sender to you:
It never actually sent. A lot of people don't even notice that a message is sitting in their outbox, unable to be sent for any number of reasons.
The mail client successfully sent it to the SMTP server, but the SMTP server hasn't been able to forward it on to the next hop.
The message was accepted by the receiving server, but...
The message was delivered somewhere in your account, but...
Source: I administrate email servers.
Because the majority of person-to-person personal email messages flow easily through the mail system and are delivered near-instantly people take that speed for granted and treat email like an instant messenger. Under certain circumstances your perfectly legitimate, 3-word email might take several minutes, hours, or even days to be delivered.
Be patient.
Things can go wrong in lots of places.
E.g. mail follows a path from server to server. One of those could have crashed after receiving the mail but before passing it on.
Or it could have been identified as spam. Depending on your source 95% to 98% all email is undesired spam. Some of those are recognized and put into a special folder. Some of them are simply dropped without notification. I've had this happen to me with scanned documents (from a MFC 'printer' which 'scanned to a PDF email') at the time when PDF's were popular with spammers.
We eventually tracked down down the problem after sending simple test email only containing raw text did arrive but anything with only a PDF failed to arrive. For this you would need the help of the people managing the receiving mail servers and they will ask you some questions such as the exact time you sent your email (without that they need to go through a lot of logs. With the precise time they can at least confirm if the email was received or not).
Needless to say, ask the user to look in their spam folder before raising a problem with the relevant postmaster.