Comcast

Comcast (also known as "Xfinity") is an American internet service provider that also provides email addresses to its customers. Former customers can still have access to their comcast.net address if they've logged in in the past 90 days, but that also means many of these addresses become inactive over time.

Domains

comcast.net

Codes

450 · 452 · 550 · 552 · 554

450
450 4.2.0 <example@comcast.net> - Recipient temporarily unavailable

The email address is currently unable to receive email. Sending email in the future will most likely be successful.

452
452 4.1.1 <example@comcast.net> too many recent messages; Try again later

The email address is currently receiving an email at a high rate. Sending email in the future will most likely be successful.

452 4.1.1 <example@comcast.net> user over quota

The email address is currently receiving an email at a high rate. Sending email in the future will most likely be successful.

550
550 5.1.1 Not our Customer

This mailbox does not exist at Comcast. Check to make sure there are no typos with the address.

550 5.1.1 <example@comcast.net> recipient mailbox unallocated
550 5.2.0 Message rejected due to DMARC. Please see http://postmaster.comcast.net/smtp-error-codes.php#DM000001

The email failed DMARC and you have a reject policy. Make sure your email is authenticated and aligned with SPF and/or DKIM. Contact your email provider for more details on how to configure them.

550 5.2.0 <example@comcast.net> - Recipient unavailable
552
552 5.1.1 <example@comcast.net> recipient rejected - extended quota violation
554
host xx.comcast.net [x.xx.xx.xx] SMTP error from remote mail server after initial connection: 554 xx.comcast.net comcast x.xx.xx.xx Comcast requires that all mail servers must have a PTR record with a valid Reverse DNS entry. Currently your mail server does not fill that requirement. For more information, refer to: http://postmaster.comcast.net/smtp-error-codes.php#554
554 xx.comcast.net comcast x.xx.xx.xx Comcast block for spam. Please see http://postmaster.comcast.net/smtp-error-codes.php#BL000000