> A customer of ours has said that someone at a domain (shaw.ca) is emailing > her and we are blocking it. So I do some digging and sure enough: > > Jan 14 08:19:55 gumby postfix/smtpd[24503]: reject: RCPT from > shawidc-mo1.cg.shawcable.net[24.71.223.10]: 504 <snelsong@shaw>: Sender address rejected: > need fully-qualified address; from=<snelsong@shaw> to=<[EMAIL PROTECTED]>
I would refuse to. The guy only needs to go into his mail client, and add the .ca, and his mail would work EVERYWHERE! I wish his ISP was using reject_non_fqdn_sender! Email the postmaster at his ISP, and ask them to inform their user that he has misconfigured his email client. All whitelisting should be avoided whenever possible. This is because every whitelist entry is an intentional breach of your security. The chances of having any particular breach exploited are minimal. But to reduce this miniscule chance to a non-issue, don't whitelist if another way can be found. Use the ISP on the other end to fix the problem. They are doing a disservice to their customers if they do not help them, and correct this sort of mistake. Then, if they refuse, the whitelist is your only choice. I doubt they will refuse if you word things politely, and ask them just to do a small support call. --Eric
