See if this helps http://forums.b2evolution.net//viewtopic.php?t=14205
There's no easy way to configure external mail server in b2evo

I´ve already tried it, but didn´t work. Maybe because my version is 3.3.3?:(
Do you know where does b2evolution keep the data to send mails to the admin? It might be a good place to start with. :

b2evo uses internal send_mail() function as a wrapper to PHP mail(), take a look at /inc/_core/_misc.funcs.php

You should edit that function

I got into that code, tried to link part of it to phpmailer() and found myself absolutely lost. Maybe, lack of knowledge about php or about b2evolution.

SOLVED :lol:

Thanks to a good friend, I solved the problem.

He created a function called mail2 in a new php archive (which has a require ('phpmailer/class.phpmailer.php'); )

After that:

I uploaded the new function to inc/_core[/list:u]
I uploaded phpmailer archives to the same folder[/list:u]
I changed the mail() function to mail2() function in the archive: inc/_core/ _misc_funcs.php lines 2317 and 2324 and made an include with the new function like this (include('newfunction.php'); ) in the line 2313[/list:u]