We've installed domainkeys, SPF, and taken all measures suggested by Yahoo but customer e-mails continue to be delayed for days at times. And then of course they end up in the recipients junk folder. Worst of all is that Yahoo does not care to take the time to help or inform ISP's. No explanations, just generic tips. So I was wondering if there is some sort of exim or sendmail script (procmail?) we can create that will do the following: For every e-mail sent to Yahoo, the mail server sends another one to the recipient with a notice saying something like: Any way of implementing such a thing??