[Greylist-users] Forwaring mail with sendmail. Was: Which RedHat disto works best with GreyLi

Dennis Wynne DWYNNE at equinoxis.com
Tue Feb 7 15:52:00 PST 2006

If I can point out a couple of things (there were not obvious to me).

You need to edit the sendmail.mc file (in /etc/mail/) and comment out the 
line that has:

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

and add a line that has:

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

This will allow sendmail to accept Internet connections  on port 25. 
Otherwise it will only work on localhost ( on not on the Internet 

You have to rebuild the sendmail.cf file with the command: "m4 sendmail.mc > 
sendmail.cf"  while in the /etc/mail/ directory.

You can restart sendmail with: "/etc/rc.d/init.d/sendmail restart" to make 
this change take effect.

Then from another machine (Windoze or LINUX) try: "telnet xxx.xxx.xxx.xxx 
25" - where xxx.xxx.xxx.xxx is the Internet IP of the box. You should get 
the sendmail prompt and it should respond to the "HELP" command (and 

Once that is done, then DO NOT add the domains you are going to forward to 
the local-host-names file as you would if you were going to use this as a 
regular mailer for those domains.  You add them to the mailertable file 
(also in /etc/mail/) is the format:

domain.com                    smtp:[realmailserver.domain.com]

where domain.com is the domain to forward and realmailserver.domain.com is 
the existing mail server you want to forward the mail to.  What I finally 
figured out is that if you have them in the local-host-names table it NEVER 
LOOKS in the mailertable and tries to accept them for local users.

Restart sendmail as before, then try sending a message from another box to 
any account on domain.com. You can do this via Telnet if you like.
telnet xxx.xxx.xxx.xxx 25

mail from: somename at somedomain.com
rcpt to: somename at domain.com
This is a test


If you have the forwarding set up correctly, it should accept the rcpt to: 
w/o an error and it should deliver the mail to the server - so use an 
account you can read for the rcpt to: address.

You can check to be sure you have not set up an open relay by using any 
other domain in the rcpt to: line and it should refuse the mail.

Once you get it to accept and forward the mail for the domain you wish to 
protect, THEN you can start worrying about getting the greylist Milter 

This is the step I am out now - finally got forwarding to work, now ready to 
try the Milter :-)


===== Original Message from greylist-users at lists.puremagic.com (Greylisting 
Users and Developers Discuss) at 2/07/06 7:51 am
>On Feb 6, 2006, at 4:28 PM, Brent Meshier wrote:
>> I actually just installed a CentOS for this very purpose.  We have an
>> Exchange 2003 server that I need to protect.  Can any who currently
>> does this offer up a sendmail configuration that will relay all mail
>> to another mail server?
>I would actually implement this in the mailertable. It's more flexible:
>my.com      smtp:[intmail.my.com]
>and so forth.
>Greylist-users mailing list
>Greylist-users at lists.puremagic.com

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