Google Workspace – Administer Team Account with Company Email on Gmail

MX records control only the server direction (i.e. messages sent to @example.com will be handled by the server located at 123.123.123.123). It's the local mail server that decides that admin@example.com and mail@example.com correspond to the same inbox. Google uses the term nickname for forwarded addresses.

In order to create a nickname for an existing user/inbox in Google Apps, you need to do the following:

1. Go to your Google Apps admin dashboard
2. Click on Organization and users in the blue navigation menu on top of the page
3. Click on the user, to which you want to assign a nickname
4. In the User information tab (the default one) click on Add a nickname (it's right below Email quota)

There are various possibilities here:

1. As you have guessed, he keeps himself logged-in all the time, so the actual log in process does not occurs.

2. He is keeping himself logged in with a mobile device, never logging out, and the acutual log-in process does not occurs.

3. He does not uses the e-mail account given by the organisation but instead, http://support.google.com/mail/bin/answer.py?hl=en&answer=22370

4. He has some kind of Anti-Malware, Anti-Virus suite or something of that sort, which is interfering in the "Last Signed in" record keeping.