521 upstream error.

Hello! I have been using my email address for almost a year and now I can't receive any emails through with this error coming through - does anyone have a fix?

MMonsterting Hello! I have been using my email address for almost a year and now I can't rece...

Chaika•10/23/23, 3:45 PM

If you go to Email Routing -> Overview -> Activity log, what do you see there about the email?
Magic link: https://dash.cloudflare.com/?to=/:account/:zone/email/routing/overview

CChaika If you go to Email Routing -> Overview -> Activity log, what do you see there ab...

MonstertingOP•10/23/23, 3:51 PM

Just a long list of errors with emails not being received

MMonsterting Just a long list of errors with emails not being received

Chaika•10/23/23, 3:51 PM

You should be able to click and expand and potentially get some more info

CChaika You should be able to click and expand and potentially get some more info

MonstertingOP•10/23/23, 3:53 PM

Unknown error: permanent error (521): 5.3.0 Upstream error, please check https://developers.cloudflare.com/email-routing/postmaster for possible reasons why. 4VMNw1vgNMRt

MonstertingOP•10/23/23, 3:53 PM

Is the rejected reason

MMonsterting Unknown error: permanent error (521): 5.3.0 Upstream error, please check https:/...

Chaika•10/23/23, 3:54 PM

What's the destination you're forwarding it to? a gmail?

MonstertingOP•10/23/23, 3:55 PM

Its setup through the custom email feature with iCloud+ rather than Gmail

Chaika•10/23/23, 3:56 PM

If you're using the custom email feature with ICloud, shouldn't be using Email routing

Chaika•10/23/23, 3:56 PM

you're forwarding to an address on the same domain as its recieving on?

MonstertingOP•10/23/23, 4:02 PM

Okay, so would I just need to remove the email routing then?

Chaika•10/23/23, 4:04 PM

you'd need to restore the records back to the icloud defaults
https://developers.cloudflare.com/support/more-dashboard-apps/cloudflare-registrar/icloud-custom-email-domains/ shows a screenshot of what they should look like, -- probably just have the wrong MX Records/need to recreate

iCloud Custom Email Domains · Cloudflare Support docs

With iCloud Custom Email Domain , you can now purchase a custom domain right from iCloud Settings through Cloudflare and have it automatically set up …

MonstertingOP•10/23/23, 4:08 PM

Thank you ! I will give this ago and see it it works

MonstertingOP•10/23/23, 4:17 PM

Hello! that has not worked

MMonsterting Hello! that has not worked

Chaika•10/23/23, 4:23 PM

I still see Cloudflare's email routing MX records at

gardnerindustries.co.uk

gardnerindustries.co.uk

. In some cases, gmail/etc may cache the records for a bit as well, wouldn't expect it to work instantly

MonstertingOP•10/23/23, 4:34 PM

I have these at the top of the DNS records page now

MonstertingOP•10/23/23, 4:35 PM

So do I need to have anything set if I look in, Email routing - routes?

MonstertingOP•10/23/23, 5:12 PM

I'm just getting address does not exist now errors.

MMonsterting I'm just getting address does not exist now errors.

Chaika•10/23/23, 5:14 PM

Your MX addresses are still unchanged

Chaika•10/23/23, 5:15 PM

You need to disable email routing entirely, and replace the email routing MX records with the icloud ones in the screenshot of the guide. You also are lacking the spf record looks like, also in that guide

MonstertingOP•10/23/23, 5:17 PM

I have removed the custom address from email routes and I have deleted the destination email

Chaika•10/23/23, 5:18 PM

that's not enough, when you enabled Email Routing it replaced your MX Records, which decide where mail goes to. Right now, mail is just going to Email routing still and broken.
To switch back to ICloud handling your email, you need to disable Email Routing and replace the MX Records

MonstertingOP•10/23/23, 5:19 PM

Shall I delete the current records and just create new ones?

Chaika•10/23/23, 5:20 PM

The current MX Records pointing to Cloudflare, yea. You'll be unable to modify them unless you disable Email routing first though (under Email -> Email routing -> settings)

MonstertingOP•10/23/23, 5:21 PM

Okay I have done that, assuming I need to add the records shown in that link you sent?

Chaika•10/23/23, 5:23 PM

yea the two MX records going to mx01 and mx02 icloud.
You should also have a txt record on your domain starting with

v=spf1

v=spf1

, if you don't, copy that.
The DKIM one as well, which looks like it just needs to be same name, but content of

sig1.dkim.<yourdomain>.at.icloudmailadmin.com

sig1.dkim.<yourdomain>.at.icloudmailadmin.com

, so

sig1.dkim.gardnerindustries.co.uk.at.icloudmailadmin.com

sig1.dkim.gardnerindustries.co.uk.at.icloudmailadmin.com

in your case

MonstertingOP•10/23/23, 5:32 PM

Thank you very much! I will enter that and see what happens and come back to you

CChaika yea the two MX records going to mx01 and mx02 icloud. You should also have a txt...

MonstertingOP•10/24/23, 1:55 PM

Hello! I made those changes and it seems to have resolved the issue

thanks so much for your help!

user2350972087•4/2/24, 9:02 PM

Hello. Looks like I am not alone, but I am getting the following error:

Unknown error: permanent error (521): 5.3.0 Upstream error, please check https://developers.cloudflare.com/email-routing/postmaster for possible reasons why. Oi8dHH3nG3C2

Unknown error: permanent error (521): 5.3.0 Upstream error, please check https://developers.cloudflare.com/email-routing/postmaster for possible reasons why. Oi8dHH3nG3C2

Does anyone have experience with this?

521 upstream error.

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