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Re: Delivery failure - SMTP error 421

New Poster

Re: Delivery failure - SMTP error 421

This does not quite explain our recent (and ongoing) problem with our Comcast business internet service. On an email with about 10 recipients (among a few different companies), at least one of them received our message and at least 2 came back as not delivered after 24 hours due to SMTP error.
Official Employee

Re: Delivery failure - SMTP error 421

Could you send me a private message with details such as your email address (or domain), and some of the recipient addresses?





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Frequent Visitor

Re: Delivery failure - SMTP error 421

I'm getting a similar message when trying to send from one of my comcast.net addresses today.  

 

"reported error (0x800CCC67):  The server responded:  421 resomta-po-13v.sys.comcast.net resomta-po-13v.sys.comcast.net Excessive failed authentication, ESMTP server temporarily not available, please contact support.

Official Employee

Re: Delivery failure - SMTP error 421

I'll respond with the private details to help resolve this in Private Message.





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Official Employees are from multiple teams within Comcast: Product, Support, Leadership.
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Community Icon
I am an Offical Comcast Employee.
Official Employees are from multiple teams within Comcast.
We ask that you post publicly so people with similar questions may benefit.
Was your question answered? Mark a Best Answer!solution Icon
Community Icon
I am a Comcast Employee.
Please post so people with similar questions may benefit.
Was your question answered?
Mark a Best Answer!solution Icon