Sendmail and host configuration

[Beginner01]

Hello,

I have on my computer Fedora Core 4 multiple domains.
for example:
domaina.com
domainb.com
domainc.com

My hostname is .. localhost .. sorry for that

Receiving e-mails is not a problem. But sending is somethimes a problem. I get the message localhost.domain.com is not a valid domain.

My question is: how must I configure if I send something from domaina or domainb the server the domain name is the same as domaina or domainb and not localhost.domain.com??

If I telnet to my machine (smtp) then I see:
localhost.domain.com. Domaina = ip adress x.x.x.1 and domainb = ip address x.x.x.2, etc.
It must be, if I telnet to x.x.x.2 is see domainb.com.

Thank you !

 

[RhythmAce]

localhost and localhost.localdomain resolve to the loopback device. You need to associate the hostname with your eth0 or whatever interface has public access.

 

[Beginner01]

Thank you for the anwser. But I have one adapter eth0 with an ip address and 3 virtual adapters with an ip address. How can I tell to sendmail from which domain I am sending?