email being sent to users on my server being bounced?

[Homerboy]

their return error msg:

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

Mattr@XXXXX.com
SMTP error from remote mailer after end of data:
host email.XXXXX.com [216.xxx.xxx.xxx]: 554 Recipient unknown
Brendam@XXXXX.com
SMTP error from remote mailer after end of data:
host email.XXXXX.com [216.xxx.xxx.xxx]: 554 Recipient unknown


these users are on my email server and get mail perfectly fine. The sender is getting msgs bounced back. They are sending through earthlink.net

 

[dphantom]

Might look at This link. Not sure if it dexcribes your situation exactly. It talks about an Exchange server environement with Outlook Express clients and it is a 5.5 version so a bit old.

 

[her209]

Turn on the logs. Look at the RCPT TO: to see exactly how its formatting the address.

 

[nweaver]

could also be bounced due to no reverse DNS for their mail server.

Are they sending FROM the earthlink mail server, or sunding FROM the earlink network with a different domain name?

 

[RebateMonger]

Originally posted by: nweaver
could also be bounced due to no reverse DNS for their mail server.

I thought that Homerboy had an SBS 2003 Server, but maybe I'm wrong. If it IS SBS, then it's not likely it's rejecting email based on lack of RDNS, since Exchange can't reject emails based on that criteria without programming or 3rd-party help (unless SP2 has something hidden to handle RDNS rejections).

Here's how SBS's Exchange SP2 server will respond when a recipient name doesn't exist (I just tested this with an SBS Server by removing a previously-valid email address):
------------------------------------------------
Your message did not reach some or all of the intended recipients.
The following recipient(s) could not be reached:

miker@xxxxxx.com on 11/2/2006 3:13 PM
The e-mail account does not exist at the organization this message was sent to. Check the e-mail address, or contact the recipient directly to find out the correct address.
<yyyyy.com #5.1.1 smtp;550 5.1.1 User unknown>
-----------------------------------------------
When troubleshooting mail issues, I always start with an examination of the sending and receiving domains via http://dnsreport.com. DNSReport's "Mail Test" is a quick way to test the validity of an inbound email address on the receiving side.

On both sides, look for ANY critical errors and get them corrected.


I don't know WHAT a "554 Recipient unknown" really means. Frankly, I find email error messages really confusing, since they often don't tell the real reason for the rejection and the same error code is used for many different purposes.

In general, as nweaver notes, a 554 error points to a "Transaction Failed" error. For instance, when the connection was rejected because of anti-spam or RBL blocks, or there was no RDNS listing for the sender's email server. Or the data exchange somehow got corrupted during the message transfer process.

her209 suggested this kind of error, suggesting looking at the format of the RCPT TO: address. It's almost like the sending server isn't sending the data in a way that the receiving server understands, and the "Recipient" isn't being transmitted properly to the receiving server.

Wish I could be of more help.