- For individual users
- Instant access to solutions
- Ask your tech questions
- Start your 30-day Free Trial
Main Topics
Browse All Topicsi used have one site have two server windows 2003 standrad Edition both are domain controller, one of them have exchange 2007 sp1 installed with mailbox rule,Hub Transport rule and client access while the other server used as a stanby cont. Replication server.
every thing was working fine until we installed a new windows 2003 Entrp edition domain controller with exchange 2007 sp1 with mailbox rule,Hub Transport rule and client access on another site,
than we notice that we cannot send or received mails between the both sites,
the mails are stuck in the queue with error message "451 5.7.3 Cannot achieve Exchange Server authentication"
while the users in the first site can send and received mails from outside.
note that the server in first site has two network interface, the 1st to communicate with its LAN the 2nd to communicate with second site.
please advice....
This Question has been solved and asker verified All Experts Exchange premium technology solutions are available to subscription members.
Experts Exchange has been collecting answers to technology questions since 1996…3 million and counting! If you have a question, chances are we already have your answer.
If you can't find the exact answer you're looking for, ask our exclusive community of 50,000 experts. You’ll get a personalized answer from a trusted professional.
Thousands of free tech tips, tricks, how-to’s and tutorials are available in our peer reviewed articles section. See for yourself how smart our experts are, no login required.
Access the answers to your technology questions today.
30-day free trial. Register in 60 seconds.
Members of the expert community talk about why the experience at Experts Exchange is different than what you will find anywhere else.

Try it out and discover for yourself.
30-day free trial. Register in 60 seconds.
Join the community of experts here and help other tech pros by answering question in your area of expertise. You can earn FREE access to all Experts Exchange's premium features and resources.
Business Accounts
Answer for Membership
by: rhandelsPosted on 2009-07-17 at 05:01:13ID: 24877775
I've found 2 articles that actually have the same issue you are having.. Check and see if it helps you.. ;)
e.com/Soft ware/Serve r_Software / Email_Ser vers/Excha nge/Q_2263 8022.html
osoft.com/ Forums/en- US/ exchang esvrtransp ort/thread /0e1bac67- 027e-43c0- 9b12- 6adf5 9710d08
To give a brief description of them.. Look at your SMTP connectors from both servers to eachother, check to see if windows authentication is enabled and make sure both SMTP connectors are using port 25..
http://www.experts-exchang
http://social.technet.micr