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Dominic P
Asked: 2014-11-13 10:14:49 +0800 CST

Appropriate PTR records for mail server [duplicate]

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I realize this is a common question around here, but I'm having trouble understanding one part of it. I want to setup a mail server to send newsletters and other marketing emails for a few of my domains. Obviously, deliverability is very important, so I want to make sure I have the PTR records right.

So, let's say I have 2 domains that I want to send mail for: example1.com and example2.com. I have my mail server setup on a VPS that's accessible at example1.com. I have a PTR record for example1.com's server's IP address (e.g. 1.1.1.1) that points to example1.com.

Now, if I want to send mail using my mail server from [email protected], would I have a PTR record problem? I imagine the receiving mail server getting a message from a server with an IP address of 1.1.1.1. It checks the PTR record for that IP and get's example1.com. It then looks and sees that the email is coming from example2.com. Does this matter?

Sorry for the basic question, I'm just having a hard time understanding this particular situation.

email-server

3 Answers

  1. The PTR reverse record is supposed to point to the canonical hostname of the server, it's not directly tied to any email addresses.

    Ie, the PTR record should probably point to something like zeus.example.com.

    This has no actual implication regarding which domains the server is expected to deliver mail for, it's just a sign of a correctly set up environment.

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  2. Best Answer

    The receiving mail servers just want to see a valid PTR record when they query. It doesn't have to match the domain in the email.

    For example: Let's say you host emails for domain1.com and domain2.com at 1.1.1.1 When the receiving server does a query on 1.1.1.1, they just want to see a domain come back. It doesn't matter if it is domain1.com, domain2.com, or hithere.com, just so long as it doesn't come back with a non-existant domain response.

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  3. If you want reliability then you'll want to make sure your email/marketing domains specify your e-mail server in their SPF record. Also, amongst other things, you'll want to throttle the amount of e-mails you're sending per hour/time interval.

    http://www.openspf.org/FAQ/Examples

    Check your domains and the e-mail server's IP via the RBLs to make sure it's clean (periodically as well).

    http://www.anti-abuse.org/multi-rbl-check/

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