What if you made your users have a GMAIL account to use your AIM SAAS app., and
as part of their user setup, they entered their own gmail credentials.
When sending emails from your app [ this is not talking about system messages, past due notices, thanks for signing up, etc ], you populate the fields in the OutgoingEmailAccount for the LIRU, and then use that in the send.
SEND Email TO OutgoingEmail.CRM_Contact USING OutgoingEmailAccount
This way, that actual person's Gmail account is used, and replies/bounces comes back directly to them.
You'd login regularly to the user's email account to retrieve any business emails and tie them to you comm. history.
I'm not able to get the FROM and Return-Path SMTP headers to work correctly in v8, so this seems like this would work without having to use/pay for an outside email service.
jaymer...