While sending a lot of emails on a busy day, have you ever sent a message saying you attached a file but forgot to include it? Outlook 2013 includes a handy feature that reminds you if it appears you forgot to attach a file.
Outlook 2013 Attachment Reminder
The setting should be enabled by default, but if not, go to File > Options > Mail then under the Send Messages section, verify that “Warn Me When I Send a Message that May be Missing an Attachment” is checked.
Here’s the typical scenario: You compose and email letting the recipient know you’ve attached a file, but forget to actually include it and hit Send.
Outlook will give you an Attachment Reminder message. Click Don’t Send, attach the file, and send the message.