When the system send a new user the welcome message the email address is in the format of [email protected].. If they reply to that it will bounce, if it gets there at all if their mail server does DNS lookup. How can I change the admin email.
Exim is the one that decides who the mail is from. Since the code is running as "admin".. exim naturally decides that the email should be from admin@hostname. This could be helped by just adding a Return-path header. Unfortunately, it's hard coded, so the headers can't be changed. I can look into adding a setting so you could specify who the mail will be returned to.
user@hostname *is* a valid email address on the server and will get to your system email account, but only if the proper MX records are created for the hostname.
The user who creates the account will be in the From field as user@hostname. I'm will add the ability to specify the From/reply email, as well as the name that will be displayed.