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Tell HN: Make sure to configure DKIM/SPF with Fastmail

by whichdan on 3/27/22, 8:27 PM with 24 comments

I've been using Fastmail since 2007, so I haven't touched the DNS of several of my domains in years. All of my email has been getting flagged as spam by GMail recently, and it's likely because I never added DKIM/SPF records to my older domains. I know there are a bunch of old Fastmail users here so figured I'd do a quick PSA
  • by johngalt on 3/27/22, 10:23 PM

    Not unique to Fastmail. Any domain that sends email should have DKIM/SPF/DMARC. SPF is quickly becoming irrelevant, but it is an easy configuration item.

    Recommend mxtoolbox for validating configurations https://mxtoolbox.com/

    Specifically send a test email to ping@tools.mxtoolbox.com and it will advise you of your current settings.

    Dmarcian has good resources on DMARC specifically, and can act as an RUA report reader as a paid service. https://dmarcian.com/alignment/

  • by climb_stealth on 3/27/22, 9:56 PM

    When you manage your domains through Fastmail it does it automatically. I certainly haven't had to configure it myself.

    There is a neat website to check your email settings that was on the HN front page earlier this year:

    https://www.learndmarc.com/

  • by walrus01 on 3/27/22, 8:56 PM

    In general, never have an MX configured in your authoritative DNS zonefile without proper SPF and DKIM. Deliverability to outbound SMTP destinations will be very poor.

    Not fastmail specific.

  • by RKearney on 3/27/22, 9:11 PM

    This is true of any mail service and is not at all unique to Fastmail.
  • by 2000UltraDeluxe on 3/27/22, 8:33 PM

    Also add DMARC to the list aswell, and make sure to warm up the domain again once you're done.
  • by iamdamian on 3/27/22, 10:54 PM

    Agreed, and thank you for the PSA.

    This hit me a week ago. After a friend let me know, configuring DKIM/SPF did the trick in minutes.

  • by MerelyMortal on 3/28/22, 2:45 AM

    I added DKIM/SPF over a year ago, and they still sometimes get flagged. It doesn't help that one sad/spiteful person marked it as spam in his Yahoo account (at least I was notified that someone did, and because I'm not actually a spammer, I quickly figured out who it was).
  • by benibela on 3/28/22, 12:04 PM

    I have a custom domain on shared hosting, and apparently the hoster does not support DKIM.

    Is that really bad?

    I sent a mail from it to a gmail account, and it was not flagged as spam

    Also, when I send a mail from my university address, it says, the DKIM user identifier does not match the from header

  • by mmetcalfe on 4/1/22, 1:23 PM

    This happened to me, starting a few days ago. It appears to be fixed after adding the DKIM/SPF records.
  • by basisword on 3/27/22, 9:38 PM

    I know nothing about DKIM/SPF. Is there a reason this only applies to older Fastmail users?
  • by notacoward on 3/27/22, 9:21 PM

    I noticed this recent change too. Deliberate degradation of service via competitors (Fastmail is objectively not a spam relay and I'm sure the folks at GMail know that) is just more fodder for the coming anti-trust case.
  • by Amfy on 3/27/22, 8:33 PM

    thanks