Using Zimbra with external SMTP to mask address

[Robin]

Hello!

I have a question about setting up Zimbra to be used as a relay for another smtp, to be used to mask the domain for the user. I've tried to search, but could not find a similar thread.

The reason why I want to do this for my domain/company, is because we recently been merged with a larger company in the concern and we are all going to use Lotus Notes () in the future, but because Lotus doesn't have a web client at the moment, we have made a deal with the head company that we can use our own e-mail client until Lotus has release their client.

But, we want to profile us as the other company through emails, meaning we would like to use their domain after @.

How can this be set up?
What has to be done from their side?
What has to be done from our side?

Example:

I'm an employee with the address robin@ourcompany.com (a domain that WE manage) and the mother company has setup a address robin@mothercompany.com forwarding the email to robin@ourcompany.com.

I login to Zimbra with robin@ourcompany.com but when I send e-mails the one who receives it will see that it comes from robin@mothercompany.com and when he tries to reply it get sent to robin@mothercompany.com (and the forwarded to robin@ourcompany.com).

Please help!
Thank you for a great email solution!

[Robin]

I think I found it:
Managing Domains - Zimbra :: Wiki

Right? Masquerade?

I've tried it and now it seems as it comes from @mothercompany.com.

I also want to actually use their SMTP server, so the can't be considered being spam right?
What do I have to do?
Is it Relaying/Domain Forwarding I'm thinking of?

zmprov
md ourcompany.com zimbraMailCatchAllAddress @ourcompany.com
md ourcompany.com zimbraMailCatchAllForwardingAddress @ourcompany.com 
md ourcompany.com zimbraMailTransport smtp:mail.mothercompany.com

Is that it or?

[phoenix]

Go to the Admin UI and set the relay there, if it needs authentication the go to the wiki and search for 'authentication'.