Solved

Exchange 2003 and Verizon FiOS

Posted on 2009-04-02
2
1,391 Views
Last Modified: 2012-05-06
Very specific issue:

Small Business Server 2003 with Exchange 2003, connected to Verizon FiOS.  Virtual SMTP server is configured to send all outbound messages through Verizon's SMTP server, and the required Verizon username and password are entered and appear to be working.

In addition to hosted mailboxes on the Exchange server, I also have several contacts that redirect e-mail to Verizon.net mailboxes.  These also seem to be operating just fine, except when the sender is a verizon.net address, in which case an NDR is sent back to the sender stating "550 5.7.1 Authentication is required to send mail as <xxxxxxxx@verizon.net>".

This only occurs when the sender is a verizon.net address.  All other internet senders' e-mail is relayed and delivered without issue.

Can anyone provide any insight as to what may be causing this?

Thank you.

Dimarc67
Columbia, MD
0
Comment
Question by:Dimarc67
2 Comments
 
LVL 4

Author Comment

by:Dimarc67
ID: 24063495
Further info--

I've been able to confirm that in the scenario of relaying inbound e-mail sent from a Verizon sender, only e-mail sent under the username and password that is entered in the virtual SMTP configuration is relayed.  But the odd thing is that all e-mail sent from non-Verizon senders is relayed without issue.

Would anyone else besides me speculate that this is some sort of side-effect of Verizon's authentication routines?  Can anyone suggest a solution to this?
0
 
LVL 65

Accepted Solution

by:
Mestha earned 500 total points
ID: 24065363
Almost certainly it is down to their spoofing controls, and that is pretty clever that they are doing that. It is probably to ensure that users don't spoof as other Verizon users.

As for a resolution, the only one I can think of is to use another server outside of Verizon to bounce the email off. The type of forwarding that Exchange does will make the message look like spoofing.
Another one would be to not use a smart host for email to the Verizon address. Email to Verizon will be entering their network via different hosts, which are setup in a different way to the servers you route outbound email to.

Also it isn't good practise to have the smart host set on the SMTP Virtual server. It should be set on an SMTP connector which will allow you to deliver email correctly.
If you want to try routing email directly via DNS for verizon addresses then you will have to make this change as you will need two SMTP Connectors - one for the smart host and one for the Verizon addresses.

Simon.
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

We are happy to announce a brand new addition to our line of acclaimed email signature management products – CodeTwo Email Signatures for Office 365.
Marketers need statistics and metrics like everybody else needs oxygen. In this article we explain how to enable marketing campaign statistics for Microsoft Exchange mail.
In this video we show how to create a User Mailbox in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.: First we need to log into the Exchange Admin Center. Navigate to the Recipients >> Mailb…
In this video we show how to create a Shared Mailbox in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.: First we need to log into the Exchange Admin Center. Navigate to the Recipients >> Sha…

910 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

21 Experts available now in Live!

Get 1:1 Help Now