We help IT Professionals succeed at work.

Email problems, reverse lookup?

globalwm asked
Medium Priority
Last Modified: 2012-08-13
We just switched over to Verizon as our DSL carrier and are starting to have some odd issues.  I am sure it has something to do with the DNS settings an reverse lookups for the remote mail server in that ours is registering with the internal name (netbios_name.domain.com) and the IP address is registering as the big long nasty thing from Verizon (see below) and the two are not matching.  Have you seen this and do you have any suggestions?

You do not have permission to send to this recipient.  For assistance, contact your system administrator.
            <netbios_name.domain.com #5.7.1 smtp;554 5.7.1 <verizon static IP>: Client host rejected: Please use your ISPs Mail Servers.  Goodbye. CLIENT>

Do I just need to add the mail.domain.com to the smtp virtual server setting?  (Exchange 2003, spt2)
Watch Question

Expert of the Quarter 2009
Expert of the Year 2009
You need to get your ISP to change the reverse DNS entry to host.example.com (ie what the DNS host is). It would appear that the remote site is rejecting the email because it looks like a dynamic IP address.

You need to set the SMTP virtual server correctly as well, but if the reverse DNS is wrong then that will be the primary rejection method.


Not the solution you were looking for? Getting a personalized solution is easy.

Ask the Experts
Access more of Experts Exchange with a free account
Thanks for using Experts Exchange.

Create a free account to continue.

Limited access with a free account allows you to:

  • View three pieces of content (articles, solutions, posts, and videos)
  • Ask the experts questions (counted toward content limit)
  • Customize your dashboard and profile

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.


Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.