How to block specific mail to a user?

Question

Email

Good afternoon.
It is necessary to prohibit personal mail in the office, but the problem is that work and personal mail are on the same domain and simply pushing the domain into an emergency will not work.

For example:
[email protected] and [email protected]

Is it possible to somehow get the username and deny access to all mail names except [email protected]?

Answer 1

More likely no than yes. Only through some crutches. Deny access to the mail site and leave only ports for mail. Install Thunderbird and connect corporate mail there. Prohibit Thunderbird like adding other accounts.

Answer 2

The only thing that comes to mind is the prohibition of direct connections and local Mail with the Mail collector. And on this mailer, either with scripts or regexps, set up a
white
list

Answer 3

99% that this is impossible without your own mail server

Answer 4

This is possible, for example, if you put a browser extension in the office on all browsers, which prohibits all other email addresses, except for work ones. There are other ways. But there are a lot of nuances here.
And the main nuance is whether there is a ban on personal smartphones (from which you can also read personal mail). If there is no such ban, then there is no point in banning mail on office devices. And if there is such a ban, but not for the sake of information security, but to increase the working time of employees, then this is complete nonsense. In the second case, it is better to simply recommend that you use personal mail less often, and fire the most impudent ones based on their low productivity (and not on the fact of using personal mail during working hours).