the web service sends out emails on behalf of the users to their customers. So john@domainA.com uses webservice and webservice sends emails . The emails should be appearing as coming from john@domainA.com.
Currently what we are trying to do is to configure webservice to act as an email client for each user, each user being able to create their own profile in which they need to configure their smtp server credentials. But given that there are more options for configurations than you can shake your stick at -not to mention trying to explain to users what info to get from where, POP b4 smtp, TLS, SSL, AUTH,etc) I am wondering if there could be a different way.
How, if at all could this be approached? Can I set up a postfix server to do what I need to without running into another admin. nightmare or being blocked for spamming?
Thank you for your insights