Gmail Throttling Listserv Mail

• J

  Jay

  4/5/26, 5:20 PM

  MDaemon v.25.5

  Gmail is throttling listmail as shown below when list members send from gmail accounts.  SPF and DKIM pass but DMARC fails due to header.  Is there a solution for this?

   

  Sun 2026-04-05 14:52:37.061: <-- 421-4.7.32 Your email has been rate limited because the From: header (RFC5322)
  Sun 2026-04-05 14:52:37.061: <-- 421-4.7.32 in this message isn't aligned with either the authenticated SPF or
  Sun 2026-04-05 14:52:37.061: <-- 421-4.7.32 DKIM organizational domain. To learn more about DMARC alignment

  0 likes 0 likes Liked Like

  ---

  8
  Posts

  109
  Views

  Reply

  ---

• A

  Arron Admin Staff

  4/6/26, 7:21 AM

  Go to Main | Mailing Lists Manager | Select the List | Edit | Headers, check the box for "Replace 'FROM:' with List's name and email address" OR "Replace 'From:' email address with list's email address if message is sent from a domain that publishes restrictive DMARC policy"

  The first option will always replace the From header of messages sent to the list, the second option will only replace the From header when the senders domain publishes a restrictive DMARC policy.  

  You can find more information in the help at:

  https://help.mdaemon.com/MDaemon/en/ml_headers.html

   

  --
  Arron Caruth

  0 likes 0 likes Liked Like

  ---

• J

  Jay

  4/8/26, 6:34 PM

  That box is checked.  What I found is this only happens when this member uses Outlook connected through Gmail.  All of the emails addressed to Gmail end up in the retry Q.  However, if sent from Gmail/Browser this does not happen.  I created a test Gmail account in Outlook and sent a test post and this did not happen.  Another Gmail member that uses Outlook was successful, as well.  This is occurring with only one user.  I asked him to remove and reinstall the Gmail account in Outlook and retry.  Very odd behavior.

  Thank you for the response, Arron.

  Jay

  0 likes 0 likes Liked Like

  ---

• A

  Arron Admin Staff

  4/9/26, 6:11 AM

  That box is checked. 

  Which box specifically is checked?

  The error message indicates that the FROM header is not aligned with the SPF results or DKIM signature.  This leads me to believe that the FROM header has not been changed to the lists email address.  If the FROM header is using a gmail.com address, which publishes a restrictive DMARC policy, then the FROM header should have been changed.  That leaves two options that I can think, 1. Outlook is configured to use a domain other than gmail.com in the FROM header when sending the mesage and that domain does not publish a restrictive DMARC policy, and you only have the option enabled to update the FROM header when a restrictive DMARC policy is published.  2. MDaemon didn't do a DMARC lookup so it doesn't know the header needs to be updated.

  In order to figure out what is happening, I'll need a copy of the MSG file that is causing the error to be generated from MDaemon's remote queue, a copy of MDaemon's logs that show the message being accepted, processed, and attempts at delivering the message, and a copy of the mailinglist@domain.com.GRP file from the MDaemon\app directory.

  --
  Arron Caruth

  0 likes 0 likes Liked Like

  ---

• J

  Jay

  4/9/26, 5:02 PM

  @Arron Replace 'From' email address with list's email address if message is sent from a domain that publishes restrictive DMARC policy IS checked.  Replace 'From' with List's name and email address IS NOT checked.

  0 likes 0 likes Liked Like

  ---

• A

  Arron Admin Staff

  4/10/26, 6:27 AM

  Without more inforation.... My best guess is that the From header of the message is using a domain, not gmail.com, that does not publish a restrictive DMARC policy.  

  Does the issue go away if you check the box to Replace 'From' with List's name and email address?

   

  --
  Arron Caruth

  0 likes 0 likes Liked Like

  ---

• J

  Jay

  4/10/26, 8:26 PM

  Well, I went in to copy and paste one of the delayed posts in the Remote Q and I happened to see, From:  To:  and CC:  populated. CC: had the same gmail address as To:  That caught my eye as I have not seen that before.  I asked the member to only use To: and From: no CC: and the test went through successfully without any defferment.  I'd love to hear your explanation why this broke list mail going back to gmail from a gmail user via Oulook.

  Thanks for hanging in there with me, Arron.

  Jay

  0 likes 0 likes Liked Like

  ---

• A

  Arron Admin Staff

  4/13/26, 6:12 AM

  I'm not sure why gmail would be throttling messages because an address was provided in the CC field, but I'm glad you were able to resolve your issue.

  --
  Arron Caruth

  0 likes 0 likes Liked Like

  ---