Troubleshooting mail delivery (Exchange 2010) - receiving from relay

[Ric_]

I'll explain the complicated setup I have initially...

 

1. LancsNGfL mailserver accepts mail destined for our domain

2. The LancsNGfL mailserver then relays that mail to an IP address

3. The IP address mentioned in 2 is then nat-ed with a port forwarding rule to my Zimbra server

4. If the Zimbra server does not have the recipient, the mail is relayed onto my Exchange server

 

Now the problem...

 

I'm decommisioning the Zimbra server so there's now no accounts on it. My Exchange server is sat happily receiving mail.

 

If I change the port forwarding rule to point to the exchange server (which has a recipient rule on it accepting mail from thew LancsNGfL relay), I stop receiving mail. Changing the port forwarding rule back fixes the problem.

 

What am I missing?

[Domino]

is the relay security enabled? maybe its not receiving any auth so disregarding it?

[Ric_]

is the relay security enabled? maybe its not receiving any auth so disregarding it?

 

AFAIK there is no security... none was set up previously so I have simply set it to accept anonymous connections on the receive connector. However, I just telnet-ed to the relay from my exchange box and it turns out that the relay is also running Exchange. Perhaps the two Exchange boxes are trying to get too clever

 

EDIT - Maybe ticking the 'Exchange Servers' authentication box in the receive connector will work?

[Hollie1985]

Check config, relay settings? The IP address, mailbox on the exchange ????

[leco]

Could you have LancsLGfL send mail to the IP of the server hosting Exchange. Or move the IP address from the decommissioned Zimbra to an additional one for the Exchange server perhaps?

[kmount]

I don't know an awful lot about Exchange but I suspect at the moment it is quite happily relaying for the local network (so it's taking from zimbra no problem). In your Zimbra you'd have defined the upstream mx / smarthost I imagine so that would be working as you'd expect.

 

In short, does exchange need to be told about lancslgfl?

[rob_f]

Is the Exchange server currently sending directly out, or is its return path through Zimbra? Just trying to work out firewall/routing wise if everything is OK with it... i.e. check the gateway, any outgoing firewall policy, maybe you have a source mapping set up for Zimbra that Exchange doesn't have, and the Lancs relay refuses to talk to anything but the external IP mapped to Zimbra?

 

Few thoughts after your plea on twitter ;-)

[Ric_]

In short, does exchange need to be told about lancslgfl?

 

I've told it in multiple ways unfortunately.

 

Is the Exchange server currently sending directly out, or is its return path through Zimbra? Just trying to work out firewall/routing wise if everything is OK with it... i.e. check the gateway, any outgoing firewall policy, maybe you have a source mapping set up for Zimbra that Exchange doesn't have, and the Lancs relay refuses to talk to anything but the external IP mapped to Zimbra?

 

Sending via the smarthost works fine (I've changed the source mapping for that). I also changed the port forwarding rule so that the same external IP address is used for the Exchange server as was used for the Zimbra server.

 

I have also tried playing with the hostname reply that Exchange gives out - I'm wondering if they have specified a particular hostname for 'security'.

[Ric_]

Tried fettling it again to no avail... this is quite annoying and very strange

[john]

What do Lancs ngfl say? Can they see you?

[Ric_]

What do Lancs ngfl say? Can they see you?

 

I got bored with trying and figured I'd come back to it later I'm going to have another go next week.