Outlook 2003 Error Message 550: Relaying not allowed

[solicester]

Using Outlook (not Express) 2003 on a home network (2 machines) with XP Pro. The machine in question is the principal machine on the network.

My ISP is optonline and my connection is by cable modem. I have always had all of my email accounts configured to use the correct SMTP server (mail.optonline.net) for outgoing mail.

I have twice verified with my ISP that they do NOT (for now) block relaying and that they do not require authentication for outgoing mail.

The problem is that randomly(of course!)when I click "Reply" and compose and send emails to any of a wide range of addresses (it's definitely not just one domain that causes the problem), I immediately receive the following (apparently) locally generated error message:

------------------------------------
Undeliverable: (no subject)

System Administrator

Your message did not reach some or all of the intended recipients.

Subject: RE: (no subject)
Sent: 05/05/04 15:07

The following recipient(s) could not be reached:

'Marber@aol.com' on 05/05/04 15:07
550 5.7.1 Relaying not allowed: Marber@aol.com
--------------------------------------------

I inquired of my ISP, of Zone Alarm, and of Norton Anti-virus, and their tech support reps say that this error message is not generated by their program.

I've tried to research this on the web, even on this site, and can only find explanations that presuppose the use of an SMTP server to which one is not connected. Again, this is not my problem.

I just cannot see any one feature of those email messages that bounce back that would be the clue as to why they do so.

One more thing, when the error message arrives, all I have to do is go into "Sent Mail," open the offending message, click "Resend this message" and without making any changes to it at all, it is always sent successfully???

Any help is appreciated. Thanks.

 

[redwhip]

It could be that one of your isp's mail servers are on a spam blacklist.

When you connect to your isp's mail server using it's hostname that name can resolve to any number of ip addresses using a DNS feature called round robin.

If only one of these addresses is blacklisted then that would explain why it only happens occasionally.

If you do
telnet your.smtpserver.hostname 25
a few times you should see it connects to different addresses each time.

You can then look up the telnet smtp commands on the internet and see if you can send messages from each of these servers.

If you check the internet headers of this bounceback message to see which mail server sent it to you?
Is it one of AOL's mail servers?
They are notorious for blacklisting.

Redwhip

 

[solicester]

Thanks for your reply.

The bounceback message has no internet header at all. This is one reason that I'm assuming that it is generated by Outlook itself or by some other program on my machine.

The other reason is:

I never download mail from my POP server without looking at it while it's still on the server and these bounceback messages never appear on the server at all. Instead, they instantly appear in my Outlook Inbox.

Any other ideas. This is causing me big problems. Yesterday I didn't notice that a time critical email had bounced back until it was too late. It would be great to get this solved.

 

[SnailUK]

I too have the same problem and as this thread seemes to have died in May I wondered if anybody has the answer?