we use a php library phpmailer. why do you want to chmod  it? what are you trying to achieve or what is the issue you're having? 

Oh well i have an Mailissue (Spammail form my machine)  and i think and i misconfigured the CHMOD of oxwall and i'm trying to troubleshot the issue.

I'm sorry, if I understood you correctly your site sends spam or what,  please elaborate the issue? 

Yup that's what I'm thinking. via the php Mail feature. But maybe I'm mistaken. So where is it in the oxwall folder.

There are several files two being: 

ow_core mailer.php

ow_system_plugins/base/bol/mail_service.php

dont go messing around in there if you dont know what your doing please.  You break it you fix it.  

also i think you are attacking this the wrong way.  First you have to be sure the issue exists. You say that you "think" your sending spam, well you need to confirm that first. If you are on a shared server then contact your host and let them know your suspicion and they can help you confirm one way or the other. 

If you are on a VPS or DED then do the same but it is more up to you to do this than them.  Check your email logs to see what exactly is being sent and when.  That will not only help you confirm the issue one way or the other but if there is spam it will help your investigation as to how it is being sent and from where. 

Then you can find the "rat file" as i call it and deal with it.  This will also help you to discover how you obtained the "rat file" in the first place if there is one.  

The first three things i would do right now is:  

change your pw for your cpanel or whatever you use and make sure it includes the webmail side of things as well when you change it (it should tell you when the pw change processes) 

change the pw for any webmail accounts you have.

contact your host to begin the initial investigation 

please keep us posted ;)