MX records / priority / rejected messages

[hkxuser]

OK here's my situation. I am supporting a client that currently uses 14 Godaddy POP accounts for email. This client recently purchased an SBS 2003 server, so I planned on having mail directed to their new Exchange server. I set up a new MX record, ptr record for the exchange IP address, etc. All was going well until I remembered they would need to purchase some additional CALs since their server only came with 5. They do not want to spend the money for the CALs, but still wanted me to set up the three office workers with an exchange account (so they could use all the exchange collaboration stuff) and leave everybody else (who are remote users) using Godaddy POP accounts. I told them this was impossible, but upon further review I'm thinking it might be doable.

My idea is to set the MX record for the exchange server at zero, and then set the Godaddy MX record at 10. So if somebody sends a mail to a legitimate user on the exchange server, the mail is accepted. If somebody sends an email to one of the POP account users (which would not be a user on the exchange server), the exchange server would reject it and then the sending mail system would try the Godaddy server and the mail would be accepted. Would this work? It seems like it should, but is there something I'm not thinking of? Is this not good "internet etiquette"?

Thanks in advance for any help or advice.

 

[GunnarD]

No, that will not work.

Mail will be sent to the mailserver with lowest MX record if that machine dosent answer att all, mail will be sent to the next mailserver.

If the first mailserver respons with anything (accept, reject ...) the sending mailserver does not try the next MX record.

 

[wkim623]

Gunnar is correct. This would not work.

 

[elgrandeperro]

I am not an Exchange guy, but doesn't Exchange have a forwarding mechanism so you could "accept" the mail on your exchange server then forward it back out to Godaddy? I don't think that counts against the CAL license because no mailbox is created and no client is accessing the server. You need to add all the forwards and any new forwards, however. And how you address the email so that your Exchange-only users get their mail.

 

[hkxuser]

I appreciate the comments guys. I wondered if there was a difference between a server not responding, as opposed to rejecting a message when it comes to MX records. You helped to clear that up for me.

As for elgradeperro's comment, I don't know how that would work. What I'm trying to get away with is having email bound for somecompany.com live on two different servers, with some users on one server and some users on the other. If I make a forwarding account for john@somecompany.com on my exchange server, how I would forward it to his godaddy account when it is named exactly the same way? I thought I had found a clever way around the problem, but I don't think it can be done. If anybody has an idea though I would appreciate hearing about it! Thanks!

 

[elgrandeperro]

I've done this (had users at an ISP and users on exchange.)
and it requires that both side have forwarding (which I think Exchange does have, but probably not GoDaddy). And the forwarding needs to be transparent such that if a user mails to @mydomain.com, both sides know if that is local or remote delivery.