emails are bouncing back when sending to yahoo

Anonymous
2024-01-11T22:32:07+00:00

getting these two error messages when sending to yahoo

1/11/2024 3:34:15 PM - Server at DS0PR14MB7526.namprd14.prod.outlook.com returned '550 5.4.300 Message expired -> 421 4.4.2 Connection dropped due to SocketError'

1/11/2024 3:24:36 PM - Server at PH0PR14MB6715.namprd14.prod.outlook.com returned '550 5.4.300 Message expired -> 421 4.4.2 Connection dropped due to ConnectionReset'

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  1. Anonymous
    2024-01-18T16:16:41+00:00

    Registrar. Just implemented a DMARC record. Will have to wait and see.

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  2. Anonymous
    2024-01-18T15:41:27+00:00

    It would have hit us all the same, just a few weeks later. And it sounds like the SPF record is irrelevant now (at least for Yahoo).

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  3. Anonymous
    2024-01-18T15:36:03+00:00

    That's the common thread. Was the change in your Microsoft DNS or your registrar DNS?

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  4. Anonymous
    2024-01-18T15:13:54+00:00

    S**t! One of the changes we made to my account involved the SPF record, and now it's fixed. We also made changes to the DMARC records.

    I like your theory of an enforcement change at Yahoo. Even so, refusing the socket hardly seems like the correct response to an SPF failure.

    Agreed that the response seems incorrect. I suppose they are more interested in foiling spoofers, so dropping the socket connection is the easiest thing to do. Not that I agree with it, just that it makes sense.

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  5. Anonymous
    2024-01-18T14:48:43+00:00

    I might have got this fixed. I found a second SPF record in DNS -- that's Sender Policy Framework, not Sun Protection Factor :-)

    There must be only one. In my case the first record was created about 10 years ago when we used a different service. That was abandoned about 5 years ago but nobody thought or new to remove the old record when they created the one for Microsoft 365. My guess is that Yahoo has made a change to more strictly enforce SPF. If you have more than one SPF record then the check will fail and your messages will bounce.

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