Incorrect name, when sending email

Incorrect name, when sending email

When my colleague puts me as cc or sends an email directly to me, then my name is not correct. It should be "Mikk Mihkel", but instead it's "martin@esto.ee", which is a third colleague's email. This is such a bizarre bug and we have found no way to resolve this. When I send emails from that account, my name is correctly displayed.

I've attached an image that shows the problem.