Frequent questions:
Hosting

The servant of salient mail of your plan of lodging uses an authentication system (he asks for user and password) to allow to send through him. This will avoid that nobody sends post office in your name through servant of salient mail of your domain.

You must modify the configuration of your program of mail so that it requires authentication to send and, in the case in which it requests it, specifying the same user and password that stops to receive (POP3).