The worst I have seen was at a former employer.
We had two people with the name "John Doe", and the mail scheme at the company resulted in john.doe@company.invalid.
The second one got... john.doe1@company.invalid
We had two people with the name "John Doe", and the mail scheme at the company resulted in john.doe@company.invalid.
The second one got... john.doe1@company.invalid
There are other ways to solve collisions: j.doe@, j_doe@, maybew one of those has a second given name, whatever.