Thanks Matti. I found a list of code explanations online, and sort of understood what you wrote. I was tripped up by the 5xx first, then another one with 4xx. I guess I'm not sure whether to remove the person or not.
Do servers ever return a 5xx, such as "unknown user" even if the user is there, say to combat spammers? Or if I get an "unknown user", is it a pretty safe bet they really are "unknown"? I'm trying to teach someone else to manage these returned messages, and I'd like to give some words of wisdom to when they should remove them and when they shouldn't. Thanks! Todd -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Matti Haack Sent: Wednesday, May 14, 2008 9:37 AM To: Todd Richards Subject: Re: [IMail Forum] Understanding Returned Mail TR> Unknown user: [EMAIL PROTECTED] TR> RCPT TO generated following response: TR> 554 <[EMAIL PROTECTED]>: Recipient address rejected: Access denied TR> Body of message generated response: TR> 451 4.3.0 <[EMAIL PROTECTED]>... First-time sender tempfailed as anti-spam TR> measure; please try again This looks like a misconfigured Greylisting. It should reply 451 at the first attempt. 4xx Errors means temporary problem, try later. 5xx means permanent error, don't retry Matti -- Matti Haack - Hit Haack IT Service Gmbh Poltlbauer Weg 4, D-94036 Passau +49 851 50477-22 Fax: +49 851 50477-29 http://www.haack-it.de To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/ To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
