Greetings

I'm trying to configure P4 for e-mail notifications.
Since I have my e-mail server, I would like to use this.

But looking at my e-mail server logs, it seems as though a server from aquariumcomputer.com is trying to send the e-mail.
It does not succeed, resulting in this error :

[05/Jan/2018 00:21:23] Failed SMTP login from aquariumcomputer.com with SASL method CRAM-MD5.

Question : Is it not possible to send e-mails direct to an e-mailserver of your own choosing, without proxy'ing through you?
Question : What does it take to use ones own e-mail server?

Best Regards
Brian