Email logs located on the server keep track of the emails that actually were sent.   If that is what you need then you will need to view those logs. 

On the other hand if you want to keep track of when the Oxwall software executes such commands and says it sends out something then you will need a plugin for that most likely as modifying core files is not recommended. 

The difference between the two is that any software can execute the mail command however it is only actually sent if the server sends it, which is why for true verification you need to rely on the server logs.

On top of that in most cases with many email clients on external email, there is no way to provide proof that the receiver actually received or opened the email.   There are some which allow that but many do not. Now with internal email messaging that is different, it can be done from within the software with a plugin which allows the sender to know if the message was read.   This is because the message stays within the same environment of the software it just changes values and locations within the same database. 

Hope that helps..

Dave :) 

Hi Dave,

Thanks very much.

I just want to keep a running log of what Oxwall software process executes. I think it is difficult to write a plug in for that, isn't it? It should be much simpler to add a small custom code to add a row t a log file whenever a notification email is sent. May ask where (which file or class) I should add such a code? Than.