On Tue, Aug 16, 2016 at 08:22:54PM +0200, Keith Williams wrote: > Hi all, > > I was wondering if someone might be able to point me in the right direction > as my searches proved fruitless. > > I am looking for a email verification system for postfix, but with a twist. > Not referring to http://www.postfix.org/ADDRESS_VERIFICATION_README.html > > The system that I am looking for should be able to include per user > interaction. What I have in mind how it should work is the following: > > - Email enters the system and checks if the sender's email address is > already whitelisted for the recipient of the email. > - If not, a pre-email is sent to the recipient requesting if the sender is > of the email is valid. Perhaps the pre-email would have 2 links (apache > comes into play), or just replying to the MTA with approve or block. > - The sender is then either permanently whitelist/blacklisted for the > recipient/user on the system. > > Per user is required as some users might want emails from a > i...@shopping.com and others not. > > Normal anti-spam measures should still apply, just this extra automation so > users can handle their own white/blacklisting from within their mail client > without having to log into additional panels etc. > > Any advice (or interest!) on such a system would be appreciated. > > Best regards, > > Keith Williams
I think you might want to take a step back and consider the actual usage scenarios before trying to come up with an implementation. It sounds to me like these are some sort of special-use email addresses, as I doubt normal personal / work email users would want to go through such trouble. Correct me if I'm wrong, here. Whitelists and blacklists are usually mutually exclusive, as they imply opposite default behavior for unlisted addresses. Decide which makes more sense for your application. Consider that if any new sender automatically generates an email if it's not on the whitelist, this may degrade the usefulness of having a whitelist in the first place. I have a suggestion based on my own way of implementing an email system, which may or may not work for you. Create a mail folder called "blacklist," and have a mail delivery script that checks incoming mail against the senders of mail in the directory. Then you can reject / redirect / spam / whatever the messages, and the mail users can add or remove entries from their personal blacklists by moving mails into or out of that folder. --Sean
