david rankin wrote: > Sandy, list: > > I have 2 situation where I need to configure a backup for our mail > server:
So, what is that situation? What exactly do you expect to achieve with a backup mx? > (1) I want to configure the remote site 3111skyline.com to accept mail > as a backup to rbpllc.com, rankinlawfirm.com, and guillorylaw.com. > > I have read > http://www.postfix.org/STANDARD_CONFIGURATION_README.html#backup > > and I have entered the MX record of: > > rbpllc.com IN MX 50 3111skyline.com In DNS the only difference between the primary and the backup mx is the priority. Submitting clients are supposed to lookup the mx records and try the servers in order of priority (lower values means higher priority). So you should have TWO mx entries in your zone. example.com_zonefile: IN MX 10 primary.example.com IN MX 20 backup.example.com > In the DNS of the domain provider for rbpllc.com > > I have made the following recommended changes and done the appropriate > postconf and reload: > > 4 /etc/postfix/main.cf: > 5 relay_domains = . . . the.backed-up.domain.tld > 6 smtpd_recipient_restrictions = > 7 permit_mynetworks reject_unauth_destination > 8 > 9 # You must specify your NAT/proxy external address. > 10 #proxy_interfaces = 1.2.3.4 > 11 > 12 relay_recipient_maps = hash:/etc/postfix/relay_recipients > 13 > 14 /etc/postfix/relay_recipients: > 15 [EMAIL PROTECTED] x > 16 [EMAIL PROTECTED] x > 17 . . . > > Is this really all there is to it??? This is all you need to make Postfix accept mails for a relay_domain. If this is the primary or the backup is merely a question of the DNS priorities. > (2) Inside the LAN of rbpllc.com, I want to designate the server > 'providence' as the backup mail server to the primary server 'bonza'. > Bonza runs DNS as master and providence runs DNS as a slave server for > the zone rbpllc.com. What do I need to do other than adding a DNS MX > entry to the zone for providence to provide this backup capability?? What you might want to think about is what you expect to happen. The backup mx will now accept mails for the relay_domain. If you do not set up a specific transport to tell Postfix what should happen with these mails it will look up the mx records for the relay_domain and if Postfix detects a higher priority mx it will then try to transfer the mails to that server (the primary). This is the default behaviour. If both mx are within your internal network you can achieve some redundancy when you set the relayhost for the internal exchange/domino server as a hostname and map both ip addresses of the primary and backup to that hostname. Then sending would work as well as receiving if either backup or primary is down. The advantage is, that this behaviour is automatic and doesn't need manual action by an admin. It is a bit more difficult if you have a firewall with NAT forwarding the smtp port to an internal server. -- Sandy List replies only please! Please address PMs to: news-reply2 (@) japantest (.) homelinux (.) com -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
