Interesting SMTP forwarding problem

[freaktechnique]

We have a user here that needs his email forwarded to an outside account. To do this we set it up using a custom recipient with the smtp account. Then modifying the original account to include this recipient.

This is how MS explains it as well as tek-tips

http://www.tek-tips.com/gfaqs.cfm/lev2/3/lev3/15/pid/10/fid/150

All mail is getting to the external address but there is one hitch. For mail that gets to us through X.400 connections then gets sent to the external account the address in the FROM: field gets changed. The name will be the same but the domain will be ours.

All the addresses in the CC: will be unchanged and all mail that originated via SMTP appears okay.

This is causing problems for this user as he cannot simply reply or reply-all since the recipient he is trying to reply to has the improperly changed domain in his address.

Microsoft has stated this is a wrong issue and states that the latest SP will fix the problem in Q254992. We are already running SP4 with hotfixes as we have this problem. We have reapplied SP4 but it didn't change anything.

http://support.microsoft.com/default.aspx?scid=kb;en-us;254992

Does anyone know a way to correct this?

 

[N0ktar]

Does this happen to all the mail that goes through X.400 connection or just to a certain sender or a certain receipient?

 

[N0ktar]

Can you type the "forward to" address in X.400 form and see if it gets delivered?
Some SMTP/X.400 gateways allow for simple-form, internet-like addressing and do a conversion to a fully-qualified X.400 address and the other way around but I'm not sure if Exchange can do that since I don't use X.400 on my site.

 

[freaktechnique]

This is only seen by the one user we are forwarding mail to through the custom recipient.

When this user OWAs to check mail this problem is not evident.

The addresses he is seeing in the FROM field are not in any way valid for these changed addresses.

As for your last question...
How could you use a X.400 email address on the Internet though? The custom recipient we have set up is forwarding email to a completely public account, with no direct connection to us.

According to what I've seen on MS KB this appears to be normal behavior.

The way I understand this is exchange uses x.400 as an internal protocol to handle messages between multiple servers on the same site and even between services on a single server. When mail is destined for an external location the mTA sees this and forwards the mail to the IMS. The IMS checks the message format and affixes an SMTP address for users with a local directory name. If the user does not have a local directory name the server creates an SMTP address for the message using the X.400 address and affixing the suffix @yoursite.com.

This address of course isn't valid but it allows Exchange to send the mail properly formatted.

So maybe there isn't a way to fix the problem, or I am misunderstanding Microsoft, (this is very possible, they are freakin confusing).