to all,

In my environment when we try to mail from our linux/unix servers, the hostname must be in public dns in order for the mail server to accept We have 80 + systems and find it a security risk to put them all in public dns. We do not have any control over the previous mentioned mail servers so I need to find a work around. We have tried a regular mail relay but that also sends the senders address which eventually get rejected anyway.

Therefore, I would like to set up a mail relay that will take the sender's address
( or at least that to the right of the @ sign) and rewrite to my predefined address.

Is this possible?

thanks.

It could be done but most servers will still reject it because it will fail a reverse dns lookup (not to mention there is enough of this crap on the internet now). I don't understand why you cannot get your mail out under current circumstances. None of your machines (other than router) actually need a public ip. Just route smtp traffic through your router to the private address on your mail server. Set your mx as a cname for your router or something like that if your don't have the ip to burn.

Tom

Tom,

Thanks for your reply.

Actually the problem is that the mail server to which we are sending these e-mails is doing reverse dns lookups and there is nothing I can do about that. They also (from past experience) will not change their configuration on their outside route for any special cases.

I should have been more clear but all I wanted was to rewrite the senders address from <user>@<hostname>.<domain> to <hostname>@<domain>. We do have a mx record just our domain which will reverse lookup.

I have been able to perform the rewrite in Exim and am almost finished doing it in sendmail.

Thanks.
Brian

In case you have not found this page, here is the masquerading page from sendmail.org

http://www.sendmail.org/m4/masquerading.html

I'd say in your sendmail.mc file you'd want to include this:

MASQUERADE_AS(`domain')
MASQUERADE_DOMAIN(`host.domain otherhost.domain')