Normally, the email notification and attachment works flawlessly right out of the box. But what happens when it doesn't? Follow along as we test a bad configuration:
Open up the Webmin interface and select the Servers menu and Sendmail Configuration option

Next select User Mailboxes

Now select Asterisk from the Read User's Mail

Now if everything worked fine, we should have no mail. If the sent email notification failed, we may have an email present. In this case, we have a returned email

Opening the email, shows that the email address has been entered in incorrectly. There is a typo, there are two periods between sait..ca when there should only be one: sait.ca

We then go back to FreePBX and correct the error in the Extension configuration.