sendmail / DNS / domains

[Fred Martin_1]

I am having difficulty with sendmail configuration. I'll try to briefly lay out the playing field:

I have three domains. The zone files for DNS are held by my ISP. The MX records for all three domains point to a single IP address.

The IP address is my sendmail server (HP-UX 10.20, sendmail 8.9.3

The three domains are all listed in sendmail.cw

My /etc/nsswitch.conf contains:
hosts: files [NOTFOUND=continue] dns

(I am not running DNS)

My /etc/hosts files lists all three domains as aliases for the server's IP address.

OK here we go:

sendmail 8.9.3 does not relay, by default. So my PC users, who POP/SMTP into my server, cannot send mail.

I used gen_cf, choosing the access_db option, created the access.db per instructions from HP, putting all three domains as OK in the file.

Still can't send mail from PCs - relaying denied.

I used gen_cf, choosing the relay_entire_domain option, and the access_db optiuon.

Now PCs can apparently send mail OK - but outsiders can relay via my sendmail server.

Quite lost at this point. Any advice? My users can't send mail now since yesterday.

Thanks

[CHRIS_ANORUO]

Put the name or ip address of your MS exchange server in the /etc/mail/sendmail.cf file as (DS'msexchangesername'). The /etc/nsswitch.conf file should have hosts: file. So that it can pick up the names from /etc/hosts files in you HP servers.
Stop and Start sendmail (/sbin/init.d/sendmail stop/start)

[Fred Martin_1]

I'm not using MS Exchange. The DS macro is null, as no one relays mail for me. sendmail should SMTP directly out to the server mail is bound for, correct?

The /etc/nsswitch.conf file does have hosts: files.

[Fred Martin_1]

This is still an open issue for me.

If I run gen_cf and set relay to ON, all works fine - except of course that anyone can relay from my server. Any attempt I've made to stop relaying, including access_db and relay_entire_domain, does stop relaying but then my PC users (on the same network as the server) can't POP in for mail.