Internet -> Postfix -> Exchange

['chris']

hi

I'm looking for Online Manual howto setup following:
Internet -> Postfix -> Exchange
Postfix gets ALL mails from Internet and sends to
MS Exchange 5.5, but Exchange sends ALL mails directly to the Internet (without postfix).

kind regards
chris

[Steven E. Protter · Accepted solution]

1) Linux server must be exposed to the Internet and configured to receive all mail. Good manuals for that are at http://www.sendmail.org

2) DS directive in sendmail.cf will forward all mail to any server you want.

vi sendmail.cf
DShostnameexchangeserver

if the hostname of the exchange server is exchange1

then

DSexhange1

Better to use the IP address

DS192.168.0.10

Save the sendmail.cf file

service sendmail restart

3) Configure the Exchange server to accept relay email messages from the Linux server.

Alternative(what I do).

The user's exchange client pulls the mail off the Linux box using popmail and stores it in the exchange database.

SEP

[xyko_1]

Hi chris,

I'm assuming that postfix is on dmz and exchange is on internal lan (behind firewall).

1 - postfix must be assigned as mx on the internet (external) dns.
2 - postfix must be configured to relay all external received mails to exchange, so, no one mail account must be defined on the server.
relayhost parameter on main.cf configuration file must point to your exchange server.
3 - exchange must be assigned as mx on the internal dns.

I think thats all.

Look for complete documentation of postfix on
http://www.postfix.org/documentation.html and take care about relaying spans on your postfix server.

Hope it helps.
Xyko

['chris']

hi

howto set mx records for the Exchange on the internal dns.
I've never done before.

kind regards
chris

[Steven E. Protter]

Its the same as any other MX record.

Microsft provides a tool under administrative tools to let you set up mx records.

Add a record with an internal ip address and restart the dns service and you should be all set.

SEP

[renarios]

Hi Chris,

don't forget to open port 25 in your iptables to enable smtp.

Cheers,

Renarios

[xyko_1]

Hi Chris,

MX records are defined in your dns server.

They point to Mail eXchange servers of your network.

Talk about with your network administrator.

regards,
xyko

['chris']

sorry, I'm a DNS administrator.
I have already created Zones for internal use, but I have never created a MX record.

[xyko_1]

Hi Chris,

MX record is another entry in your zone section.
It is simmilar to a pointer record (A record) or a name server (NS) record.

Please, look to a bind documentation to see how to configure a MX record on your dns server.
Here you have a god begining http://www.linuxhomenetworking.com/linux-hn/dns-static.htm#_Toc92808689

regards,
xyko

[Bejoy C Alias]

hi,

if u r going to use the exchange server for outgoing mails to the internet, then it is better to have a dns / reverse dns entry for ur exchange server in ur public dns servers or ur isp's dns servers as some of the servers will reject mails if the ip from which those servers are getting mails is not having a reverse dns record.

I dont have experience using postfix, but i can say that u should set the smart host ( in sendmail ) or the next hop ( to which the internal mails will be forwarded ) to point to the exchange server . For this there is no need of mx records for exchange server , only thing is that the postfix server should be able to resolve the exchange server's hostname.