ElRoc0_Tha_Gr81's profile

Visitor

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4 Messages

Friday, September 12th, 2025

DMARC error messages

Whenever I send an email most of the time they get rejected and sent back with the following " remote server returned 550 5.7.509 access denied, sending domain comcast.net does not pass DMARC verification and has a DMARC policy of reject. Can anybody assist me with what to do about this issue. Or is it an issue with comcast.net? Things that I've had this email address for approximately 30 years maybe? I do not want to have to change it and change all my contacts and update them. 

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Contributor

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444 Messages

28 days ago

How are you sending the emails?  

I assume you can send emails through the xfinity webmail page. Using their webmail or their SMTP server should work.  However, if you are using someone else's server, it should not work.

Visitor

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4 Messages

 actually use I gmail where I have it forwarded to. Have for years. Just started having issues very recently.

Contributor

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444 Messages

DMARC tells the receiving server that the email is spoofed.  However, it does not distinguish spoofing for good versus spoofing for evil and doesn't make any allowances for the fact that someone may have spoofed their own address for years.

I spoofed email addresses in the 80s and 90s too.  Somewhere around 2010, I noticed that some emails were not getting through.  I believe some email systems were already doing ad-hoc spoofing detection at that time. DMARC has formalized this and is now becoming the norm.  In my case, I was spoofing my own address at my own domain, but I realized this was basically historical, going back to a time when SMTP had no authentication and ISPs were blocking port 25.  But these things had since changed so all I had to do was point my email client at the SMTP server for my domain, and my emails now pass DMARC.

Gold Problem Solver

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26.8K Messages

27 days ago

What @strega7 said. A more technical description of Comcast/Xfinity's DMARC policy is given by @XfinityAlex at https://forums.xfinity.com/conversations/email/notice-dmarc-policy-for-comcastnet/667075ff729ad353204c8409.

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Official Employee

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1.1K Messages

27 days ago

@ElRoc0_Tha_Gr81 Thanks for adding a post. That is strange indeed. Are you using your email on the Xfinity website, or through an email app? 

Visitor

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4 Messages

actually use I gmail where I have it forwarded to. Have for years. Just started having issues very recently. It's always worked until very recently.

Official Employee

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938 Messages

@ElRoc0_Tha_Gr81​ This would have started several months ago, presuming the destination honors DMARC.  Not all do, and therefore it may have continued to work until now.

I believe Gmail has an option to send messages through our platform when acting as "comcast.net".  If you can't find this option, let me know and I'll dig a bit more.

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Official Employee

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249 Messages

Good morning @ElRoc0_Tha_Gr81, I hope you are having a good weekend so far. There is some good information in the link that was posted by @BruceW. Have you tried using the Xfinity website to email and see if the issue is happening their also?

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
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Was your question answered? Please, mark a reply as the Accepted Answer.tick

Visitor

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4 Messages

Not yet. I will and report back.

Official Employee

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623 Messages

@ElRoc0_Tha_Gr81 Let us know how it goes.

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer.tick
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