Email Routing and deliverability issues

Getting a lot of issues lately. Emails are not being delivered. How can we fixed this? I searched on the internet and found this: Email Routing 421Upstream error, bounced emails

The response from the remote server was:
421 4.3.0 Upstream error, please check Postmaster · Cloudflare Email Routing docs for possible reasons why. SB7k3doQEjkx


SPF status
pass
DMARC status
none
DKIM status
none
Rejected reason:
Unknown error: transient error (421): 4.7.0 [104.30.8.137 19] Gmail has detected that this message is4.7.0 suspicious due to the very low reputation of the sending domain. To4.7.0 best protect our users from spam, the message has been blocked. For4.7.0 more information, go to4.7.0 Why has Gmail blocked my messages? - Gmail Help b9-20020a509f09000000b005670de70d89si3472931edf.528 - gsmtp

The error message indicates that Google has blocked your domain.

If you had a spam problem or your server was compromised, and you’ve fixed the problem, you can try filling in this form: Troubleshooting for senders with email delivery issues - Gmail Help

Also, if you send a large amount of email to Gmail (more than 5,000 messages per day) Gmail now requires you to set up DKIM and DMARC.

1 Like

Same here! And I can see this is happening to many of us recently. I doubt all of us are spammers, sure I’m not. And the funny thing is that not all my forwarded/routed emails are being block, just some of them. So not sure our domains being tagged as spammers is the answer here

Might not be. Best to follow the discussion below: