Hi
I also have discussed with our exchange engineer.
Here is his suggestion!
Based on our understanding,currently, you are sending mail with a software
written by yourself, and mails from it are rejected after IMF installed.
But Exchange response 5.7.1 in NDR, which generally means "unable to
relay". This is a problem on SMTP virtual server configuration, but not
about IMF. For NDR 5.7.1, here is a part of KB284204.
Numeric Code: 5.7.1
Possible Causes:
o General access denied, sender access denied - the sender of the message
does not have the privileges required to complete delivery.
o You are trying to relay your mail through another SMTP server and it
does not permit you to relay.
o The recipient might have mailbox delivery restrictions enabled. For
example, a recipient's mailbox delivery restriction was set to receive from
a Distribution List only and non-members' email will be rejected with this
error.
o For Exchange Server 2003, a distribution list can be configured to
restrict mail delivery from unauthenticated users. Mail that is sent by
using an unauthenticated SMTP session are rejected.
Troubleshooting: Check system privileges and attributes for the contact and
retry the message. Also, make sure you are running Exchange 2000 Service
Pack 1 or later for other potential known issues.
Delivery status notifications in Exchange Server and in Small Business
Server
http://support.microsoft.com/?id=284204
He suggested that we can try two steps:
1. disable IMF and check if the problem remains
2. use a mail client such as outlook express or simply telnet to submit a
mail, check if it works
If you still have any other concern, please feel free to post here.
Best regards,
Peter Huang
Microsoft Online Partner Support
Get Secure! -
www.microsoft.com/security
This posting is provided "AS IS" with no warranties, and confers no rights.