We have a dedicated server for our website, and we also use it to send out bulk emails (ALWAYS by request, NEVER unsolicited or for spam). We are trying to set up a PTR record and there's one thing I simply can't understand: If I send out email from someone@example.com, and example.com's A record is x.x.x.x, then in order for my IP not to be considered a spammer, the PTR record for x.x.x.x must point to:example.com?any of example.com's MX records?the name of the domain as it appears in the SMTP banner you receive when connecting to example.com:25?all/none/any of the above?
Where must a PTR record point to in order to avoid being classified as a spammer?
dns;mx;spamming