I'm Redhat EL 3 with 1 domain name - www.4300.co.uk.

My server has the domain name as.4300.co.uk

I'm trying to set up the machine to send email via sendmail. I know some of you may advise me to switch to another MTA, but for whatever reason I want to use sendmail.

I've set up masquerading so that the email shows that its come from @4300.co.uk and not @as.4300.co.uk

I can send mail out no problem, but the server wont accept incomming mails.

I can send mail to another user on the box, provided the email address is 'user'@as.4300.co.uk. If I use 'user'@4300.co.uk, the email just gets held up at the main que with the message.....83.*.*.52 (IP of server) not reachable.

Can anyone guide me in the right direction please.

Sounds like your DNS server can't resolve the domain. Does adding the domain name to /etc/hosts help?
Depending on your setup you may need to add the domain to /etc/mail/local-host-names as well (and include support for that in your sendmail.cf file).

You may also need to make sure that Sendmail is configured to relay mail for your domain. This is done by putting the domain in the /etc/mail/relay-domains.

Thanks for the replies, through another thread i've found that I didnt have the following uncommented..

DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')dnl

I've uncommented this and am now getting the following error.....


----- The following addresses had permanent fatal errors -----
<robert@4300.co.uk>
(reason: 553 5.3.5 system config error)

----- Transcript of session follows -----
553 5.3.5 83.67.67.52. config error: mail loops back to me (MX problem?)
554 5.3.5 Local configuration error

I know my MX details are all correct, so where could the problem be ?

Have a look at the sendmail FAQ at http://www.sendmail.org/faq/section4.html#4.5 - this is a reasonably common problem. It's also possibly a DNS problem according to http://www.experts-exchange.com/Netw..._21648629.html, but it's worth ruling out the config issue first.