Want different hostname for external communications

[kevincurrey]

Hi there. I've done my best to research this myself, but I couldn't find where this question has been asked directly before. Any help is greatly appreciated.

I have Scalix 11 set up on running on Centos 4.4. The hostname for the server is server1.<mydomain>.local.

To the outside world I want the mail server to be mail.<mydomain>.com. That's easy to do with DNS of course, but when Scalix communicates with another SMTP server, I would like it to identify itself as "mail.mydomain.com" rather than "server1.mydomain.local."

Is this possible? Can I have a one name on my internal network, but have the SMTP server identify itself differently outside?

Thanks in advance,
Kevin

[ScalixSupport]

Hi Kevin!

To help resolve your issue try the following steps:

1. Add another domain:
In SAC, Settings -> Administration -> Local Domains -> Add Domain (mydomain.com)

2. Add alias email for all existing users, abc@mydomain.com
In SAC, Users -> Click on existing user -> Email Addresses
-> Add Address (Choose mydomain.com from the drop down) -> make this address
default.

3. In the server mydomain.com having external SMTP, in the virtualusertable file add an
entry:
abc@mydomain.com abc@server1.mydomain.local

Thanks,
Subir

[carlPjohnson]

I think the question is acutally is where do you modify the SMTPD relay for incoming email so the 250 response answers back with something other than the inside world fdqn, such as a outside fqdn. This is simple with sendmail but it seems not possible with scalix? Is that what you actually want Kevin?

[kevincurrey]

Thanks Subir and Carl for your responses. I'm pretty sure I understand what Subir was telling me to do, but it seems like that would only change my users' email addresses, which are already configured correctly. The situation is as Carl described it. When my SMTP server begins a conversation with another SMTP server, it says "ehlo server1.mydomain.local." If the receiving server has reverse dns lookup configured, it promptly rejects the message, since it can't find any records at all for "mydomain.local." So I want the conversation to begin with "ehlo mail.mydomain.com" which is already configured in my ISP's dns records.

>This is simple with sendmail but it seems not possible with scalix?

I'm not very familiar with Sendmail, but I thought Scalix uses Sendmail for its SMTP service. Either way I sure hope its possible.

Thanks again,
Kevin

[jch]

You can do it with sendmail, there are a few macros in the sendmail.cf that you need to change: the main one is $j (it's defined in a line starting "Dj"). There are probably better ways to do this in the sendmail.mc file.

However, I did this at home and it was never all that satisfactory -- the machine's real name kept leaking out into the outside world. In the end it was easier to change the hostname and have the internal name as an alias.

Having the same name inside and outside is also good: I have IMAPS and SMTPS open in my firewall so I can get to mail from, for example, here -- but when I pick up my laptop and go home it all still works because the names are the same.

I really don't like this ".local" convention that people have picked up from somewhere. Having a non-standard namespace (there isn't a .local TLD) and inconsistent naming (different names inside and outside) just leads to problems in the end.

jch

[carlPjohnson]

.. kinda off topic.

the .local thing being non real world is the whole point of it, imagine haing the same domain name internally vs external and having to deal with DNS, it throws WAY to many wrenchs into the problem and that is why everyone does that.

Windows domain perspective:

Imagine your company is ABC Inc, in the real world someone already owns abc.com and all of the like and when your users are out of your network you really can't use abc.com as the domain or some really long version of this just because of the length. So most would use abc.local as the windows domain to ease life and in the real world myalpahabetcompany.com for email, etc? Does that make sense?

Unix perspective, same as above applies and makes DNS resolution much easier to deal with so that you are not in the real world and trying to resolve abc.com which really isn''t your domain and you could use your "real" domain but again it is 30 feet long and a pain to keep care of internally for resolution.

[jch]

That must be a different DNS to the one I use then. The Cricket book goes on about having different views inside and outside the company all served off the one DNS server.

To be honest, it was *much* easier to set things up that way than it would have been to set up something that has a different TLD inside and outside.

And are there really cases where a company known as "abc, inc" doesn't own "abc.com"? I know I'm coming from hp.com, dec.com, ibm.com, samsungcontact.com (RIP) but in all those cases the internal machine names all have the same domain name.

I know that Windows loves to confuse the Kerberos realm and and the DNS domain, but does it really mean that you have to mess up your DNS and break stuff just because windows has messed up a bit?

jch

[carlPjohnson]

If you must live in a windows A/D domain and are anal about things like that, which many orgs are .. yes.