How do I configure my DNS in case of installation on 2 servers?
If you are running 2 seperate machines (1 machine running Pinjo and another machine running your original mailserver) there are different ways to configure your DNS and outgoing mail. If you have only 1 machine but multiple IP-numbers configured, the same configuration can be applied
If we are assuming that your original mail is running on IP-number 10.0.0.1 and your Pinjo mailserver is running on IP-number 10.0.0.5, you need to configure the following items:
In your DNS configure a host record for both servers. In this way your define a name for your servers
Eg. mail.acme.com for 10.0.0.1 and pinjo.acme.com for 10.0.0.5. Your A records should look like this
10.0.0.1 A mail.acme.com 10.0.0.5 A pinjo.acme.com
Configure your DNS with MX-records. MX-records contain the data for mailservers where to deliver the mail for certain domains.
acme.com is the emaildomain in this case. Mailservers will try to deliver mail for *@acme.com in first instance to the server pinjo.acme.com and if that server is not responding, they will try delivering thee mail to smtp.acme.com since the priority (5) of pinjo.acme.com is considered higher as the priority (10) of smtp.acme.com
acme.com. MX 5 pinjo.acme.com acme.com. MX 10 smtp.acme.com
In case spammers try sending to smtp.acme.com directly, remove that MX record from the DNS.
All your clients should be configured to use smtp.acme.com as there outgoing SMTP server.