Delivery failed for verification emails from [email protected]

I’m trying to set up SMTP with google for my custom domain, and to do that, they send a verification email. I’ve already set up email routing for all emails to my custom domain email to be rerouted to my personal email, but Cloudflare shows “delivery failed” and gives this error:

Unknown error: transient error (421): 4.7.28 Gmail has detected an unusual rate of unsolicited mail. To protect4.7.28 our users from spam, mail has been temporarily rate limited…

Please let me know what I can do to fix this. Thank you!

It seems Google is rate-limiting CF-forwarded emails for obvious reasons. This should be a temporary issue… and the emails should eventually go through.

A quick solution is to temporarily change your Cloudflare Email forwarding destination to a non-Google address.

But more importantly, if sending/receiving emails is important to you or your business, consider using a professional email solution with sending and receiving capabilities… instead of patching together free tools.

In the end, you may not get all you paid for: but you’re surely not going to get what you didn’t pay for :smiley:

Good luck!

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Using a non-google email didn’t work, so instead I just used iCloud+ to host.