Would it be very difficult to update stunnel and make it a configurable option to insert the originating IP as a header in the mail? ex: something like X-st-originating-IP: or something like that.
Since adding a header to each email address within a connection requires building SMTP parser - I could say it's very difficult. Probably a wealthy sponsor could make me change my mind, but otherwise such change obviously breaks the KISS principle that stunnel is based on.
Fair enough. I didn't think about the need of including the SMTP parser, etc.
What about installing an SMTP router in front with RBL support, than your anti-spam proxy, than another instance of SMTP server for local delivery? For sure it's easier than adding another feature to stunnel. I use a similar configuration for antivirus scanner based on Postfix.
Agreed - probably easier than adding this feature to stunnel. I'll have to research other options instead.
Thanks for the input/advice!
Eric