>> A few people have told me they received an email error message after >> emailing me. I'm trying to get a copy of one of the error emails, >> but I can't imagine what would cause that besides possibly my >> greylisting. Has greylisting been known to lead to email error >> messages being sent to senders in some instances? > > The sender may receive an error if their server has an unusual > setup. Such servers must be whitelisted in your greylist software.
The last sender who told me about the error message was on a comcast.net address. I found this which describes the same problem with greylisting and comcast addresses but the solution turned out to be fixing the MX record: https://discussions.apple.com/thread/3030480?start=0&tstart=0 My DNS is hosted by my domain name registrar and the MX record looks like this (but with my real domain): Host Name: example.com Mailserver Host Name: example.com Mail Type: MX MX Pref: 10 TTL: 1800 Does it look OK? > One place to start is search your mail log for errors relating to > the sender's email address and/or their server. I grep'ed my mail logs for the email address in question and I don't see anything that looks like an error. >> How is greylisting set up in postfix now? I know I used to use >> postgrey but then I remember some sort of change. I can see that I >> have postgrey installed but the service is not running. I checked >> main.cf <http://main.cf> and master.cf <http://master.cf> but I >> can't figure out how it's implemented now. > > Postfix has no "default" greylist, and there are several that are in > widespread use. Look in your "postconf -n" for a > check_policy_service entry, then find that service in master.cf. Or > some folks use a milter defined in smtpd_milters for greylisting. It turns out I'm using postscreen with deep protocol checks: smtp inet n - n - 1 postscreen postscreen_greet_action = enforce postscreen_pipelining_enable = yes postscreen_pipelining_action = enforce postscreen_non_smtp_command_enable = yes postscreen_non_smtp_command_action = enforce postscreen_bare_newline_enable = yes postscreen_bare_newline_action = enforce - Grant
