Taking Plesk to Live Environment...
Well, I haven't been able to test it out on a live environment, and from what it appears to be is that it is trying to resolve the domain and send the email. Since there is no domain name, it just ends up in an eternal loop (as it displays on the error logs).
I will test it out live with a valid domain name and see how it works.
I haven't been able to test anything else since Plesk uses Mail Enable and it seems that everything I send through it just ends up in the same place. Nothing goes out...
My test was made using the "Mail reports" option but it didn't go through .... No sure of other mailing reports on Plesk...