Redirecting email accounts to alternate mail server

[georgew]

Is it possible in scalix to specify a list of users that use an alternate email server?

Basically what I am looking for is for an email to be received by the server addressed to georgew@domain.com and recognise it as an external user and therefore forward it to an alternate mx where it is also setup as georgew@domain.com.

Thanks in advance

George

[mikethebike]

thats a very strange configuration? You have MX records pointing to your email system for another email domain?
The public MX records will only be able to point to one or more hosts, and they will have to be managed by you or someone else, there must be something in the address you would use to decide how to route.

[jangi]

Scalix can do this, but I'd need a lot more details about your setup to point you in the right direction. Here's one configuration I've used:

Public DNS MX records for xyz.com point to scalix server.
Scalix server has some of the accounts for xyz.com, but not all.
Once scalix accepts the mail, and sees that the user is not local, it sends it back out via sendmail.
Depending on how sendmail is configured, it delivers the message.
I setup sendmail to resolve using a local (private) dns server that had different MX records for xyz.com.
So sendmail would lookup that info, and route all the mail for xyz.com that scalix did not deliver locally to the other mail server.

Works great for migrations.

[georgew]

jangi ,
You've hit the nail on the head, essentially that's exactly what I'm trying to do as I need to migrate a group of users away from our internal Scalix deployment to google mail. Our current setup is as follows.

Public DNS records for xyz.com point to messagelabs
messagelabs provides spam filtering and av then forwards to internal-server

In addition I would like to configure the following steps

if account doesn't exist on internal-server forward to googlemail
googlemail checks for valid account
valid account delivered to user
invalid accounts caught in catch-all account

[jangi]

Leave public DNS pointing to messagelabs/scalix.
Make sure xyz.com is NOT in /etc/mail/local-host-names

Either setup an internal DNS server that has MX records for xyz.com pointing to google servers (and make sure /etc/resolve.conf on the scalix box points to it), or configure sendmail to route xyz.com email to google (I don't know how to do that).

I don't know how google handles catch-all, but it would have to be on their end with a setup like I'm suggesting.

Once everyone is migrated, flip public DNS to google.