iCloud+ Custom Email Domain has “too many hops” and undelivered mail

Number:rdar://FB9576843 Date Originated:2021-08-29
Status:Open Resolved:
Product: Product Version:
Classification: Reproducible:
Using iCloud+ Custom Email Domain, a third-party received an error when attempting to send an email.


Your message cannot be delivered to the following recipients:

 Recipient address: [redacted]
 Reason: SMTP transmission failure has occurred
 Diagnostic code: smtp;554 5.4.0 Error: too many hops
 Remote system: dns;smtpout.mac.com (TCP||54347||25) (iCloud SMTP - mr85p00im-zteg06011501.me.com 3.5.0 [2116B30-0009dff0785a])


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