Problem with Yahoo

[heridon]

Hi, I constantly have a problem delivering mail to Yahoo (.com .de...) All my domain emails have a SPF, DKIM and DMARC properly set up, but still, emails can't reach Yahoo accounts. In KeyHelpPro in Email Queue, I can see info... error code 421 4.7.0 [TSS04]. There is no problem with delivery to other domains and mail providers.
Does anyone know the way how to resolve this?
Thank you!

[ShortSnow]

Hi,

have you checked: https://help.yahoo.com/kb/att/new-mail- ... yEG-YLXEmW

and https://senders.yahooinc.com/best-pract ... aTSeGfZfSs

Yahoo gives you some Infos.

regards Arne

[heridon]

Hi Arne,
Thank you for being helpful. Yes, I check these two links and a few others... but there is nothing concrete there. I follow all these emails in Email queue, and there are "normal" emails, one or two per day, from my client to their partners. I check all blacklists for IP and domains and check everything regarding the mail server with mxtoolbox...((
Regards,
Heridon

[BasHeijermans]

I see this when putting the error in Google:

https://help.yahoo.com/kb/att/SLN35446.html

Error: "421 4.7.0 [XXX] Messages from x.x.x.x temporarily deferred due to user complaints - 4.16.55.1" when sending email to AT&T Yahoo Mail

This error indicates AT&T Yahoo is seeing unusual traffic from your IP address and/or that emails from your mail server are generating complaints from AT&T Yahoo Mail users.

Ergo, it seems your system, IP or your host is marked as a spammer by users.