Yes it is possible! I'm testing the same Zimbra setup here and it works well.
You must set your external mail server as mail relay in Zimbra and use fetchmail to get the mails.
To set the external server as mail relay go to Zimbras admin interface.
In the server section choose your local mail server and than click on the MTA tab. Here you can set "mail.server.com" as your mail relay.
Most ISPs are also need SMTP authentification. I used this howto to configure zimbra:
Quote:
To start you need to enable SMTP authentication on outbound messages: $
postconf -e smtp_sasl_auth_enable=yes
Next is to create a text file mapping which name/password should be used
for each given outbound destination:
$ echo mailrelay.example.com usernameassword >
opt/zimbra/conf/relay_password this is one line
Create a postfix lookup table
$ postmap /opt/zimbra/conf/relay_password
Test that the map is okay
$ postmap -q mailrelay.example.com /opt/zimbra/conf/relay_password
that should return usernameassword if done right
Make postfix use the above
$ postconf -e smtp_sasl_password_maps=hash:/opt/zimbra/conf/relay_password
Almost done. Two more changes to postfix and then we can send mail
externally. We need to change the port we listen on. This is most
important for people who use an ISP that does not allow the use of port 25
to listen to ( [i]this is most important for Rogers customers in Canada)
postconf -e relay_host=relayhost.yourisp.com:465
Your ISP might want you to use another port, so check with your ISP for an
alternate port.
Restart postfix by entering this
postfix reload |
A simple fetchmail howto i used with ubuntu:
Quote:
1. install fetchmail (sudo apt-get install fetchmail on ubuntu/debian)
2. if not exist, create the file /etc/fetchmailrc (with sudo > /etc/fetchmailrc)
3. chmod 0600 /etc/fetchmailrc
4. modify /etc/fetchmailrc to look like this
----
set daemon 600 # sets the poll interval to 10 minutes
poll mail.external.com proto pop3 #for pop3
auth password
user "user1@external.com" pass "password" is "user1@internal.com" keep
user "user2@external.com" pass "password" is "user2@internal.com" keep
----
5. To use fetchmail in daemon mode modify "/etc/default/fetchmail" and set "START_DAEMON" to "yes"
6. sudo /etc/init.d/fetchmail restart |
This should help you a little bit to configure your Zimbra server like you want it.