Results 1 to 9 of 9

  1. Post
    #1

    Email - PTR/Reverse DNS & SPF

    So we use SPF records to reduce spam.

    I had an email bounce from a recipient because we don't have a PTR/Reverse DNS record.

    It's not really my area of expertise, so i'm hoping someone might be able to give me a bit of insight into standard practice around this kind of thing.

  2. Post
    #2
    That's a bit old fashioned tbh (rdns lookup), modern systems use SPF + DKIM + DMARC. SPF being the minimum required.

    Relying on rDNS for antispam will give huge amounts of false positives.

  3. Post
    #3
    Old fashioned - that was my initial take on it.

    Turns out Vodafone turned it off after we moved a bunch of shit to Azure.

  4. Post
    #4
    PTR for your mail servers are still important to have, stupid to use it as the sole reason to bounce however.
    Normally used as part of a scoring system where not having PTR may lower your score.
    If you have SPF + DKIM should be fine without PTR but I would always add it cause of mail servers that still want it.
    DMARC is more for your own protection so others cant send using your domain and to tell other mail servers what to do when spf or dkim fails for your domains. Get them all implemented if you can.

  5. Post
    #5
    Using PTR for mail scoring is retarded in this day and age when you have CDN's, cloud and SaaS services.

  6. Post
    #6
    ^ not really, most of those cloud services are black listed or down scored too. ie for AWS if you don't use their Amazon SES email gateway thing and try and send mail directly from an EC2 instance, you will most likely get spam filtered. similar deal for azure etc etc

  7. Post
    #7
    CDN, Cloud and SaaS services have no bearing on this conversation. The sending ip should have a reverse look up if its sending emails.

  8. Post
    #8
    The sending IP should only need correct SPF records. CDN Cloud and SaaS do have a bearing. Most SaaS services sit on cloud, and are configured in a resilient and scalable way. It's fairly common to see SaaS mail services with no reverse records... because that's so 1980s.

    And very few mail systems both use reverse DNS judgements anyway. It was always troublesome, and SPF solved the issue properly.

  9. Post
    #9
    Markuchi wrote:
    CDN, Cloud and SaaS services have no bearing on this conversation. The sending ip should have a reverse look up if its sending emails.
    this