On 9/1/2013 3:30 PM, Roman Gelfand wrote: > My mail server is now bound to a public ip A. The PTR resolves fine > here. When ISP from public ip A becomes unavailable, the firewall > over to a different provider. Naturally, the mail server will now be > bound to a public ip B. What do I do if I want correct PTR querry > response? > > Thanks in advance >
Just give each IP its own unique PTR, make sure each hostname points back to the proper A record. A.A.A.A PTR mailA.example.com B.B.B.B PTR mailB.example.com mailA.example.com A A.A.A.A mailB.example.com A B.B.B.B If you want your HELO to be consistent regardless of which IP is used, use a separate hostname that points to both A records. mail.example.com A A.A.A.A mail.example.com A B.B.B.B -- Noel Jones