"451 Authentication failed: Maximum credits exceeded" error despite available email quota
Hey everyone! š
Running into a weird issue on my Pro plan and wondering if anyone else has experienced this:
Problem: Getting "451 Authentication failed: Maximum credits exceeded" errors when users try to sign up, but I'm only using 46/100,000 emails on my Pro plan (plenty of quota left).
What's happening:
- Users can't complete signup - confirmation emails fail to send
- Auth logs show the 451 error consistently
- Billing shows Pro plan active with minimal email usage
- Started happening recently, was working fine before
Already tried:
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Verified Pro plan is active and paid up
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Confirmed email quota usage is super low
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Checked auth settings
Has anyone seen this "credits exceeded" error on Pro plan when you're nowhere near the limits? Is this a known platform issue or something I might have misconfigured?
Already submitted a support ticket but hoping someone here might have insights while I wait! š
19 Replies
Are you using a custom SMTP?
I've never seen a credit error like that from Supabase, but think I have for an SMTP provider.
im using a custom SMTP for other emails, but not sign up auth
You are using the default Supabase SMTP which does 3 emails or less an hour?
Well I've increased my rate limit to 1000. But for now, yes
It does not increase for built in one. It is 3 per hour. But I've not seen a credit error.
What do you have here?
If you filled in an SMTP provider there, I believe that provider is sending back the error.
You can look in the Auth log details and possibly see more on the error.
above 'Emails' in the side tab, you can find the rate limits
Don't care about those.
What is here https://supabase.com/dashboard/project/_/auth/smtp
Your error is not that rate limit from Supabase and those settings.
That is a different message.
thats my SMTP settings, minimum interval is 60 seconds between emails. doesnt mention another limit
Please show me the SMTP tab. Are you using a provider there?
This user got the same error because they were using SendGrid...
https://discord.com/channels/839993398554656828/1399710547653427251
It was a SendGrid credit error.
interesting, yea I am using Sendgrid lol
but not for Auth emails as far as I'm aware
You are very likely though.
Can you not check the SMTP settings I linked and showed in the image.
I can, I have sendgrid set up there. not sure what i should screenshot as I dont know what not to leak lol
Fine. But you are using Sendgrid for all your auth emails then.
That is what that tab sets up.
If you have the little button set to custom SMTP then you are using that provider for all auth email.
Sounds good thanks, I wasn't aware of that. I have specific functions in my code to call the sendgrid api for other emails, So didnt think it was being used for auth
thanks
If you did not have a custom provider there, your Auth would be limited to 2 or 3 emails an hour even with Pro. But you would get a totally different error message.
yea that checks out
Update: My Smooth brain didn't realize my 60 day SendGrid Trial expired
It would be nice if Supabase would say the message is from your SMTP provider for sure.