Community Forum

421 Error when sending email IP address is not permitted to send messages

Regular Visitor

Re: 421 Error when sending email IP address is not permitted to send messages

I am having this same problem (again).

I suspect you are rejecting my VPN.

I don't see an option for PM on your profile.

 

 

An error occurred while sending mail:
The mail server sent an incorrect greeting:
 resomta-po-05v.sys.comcast.net
 resomta-po-05v.sys.comcast.net
 CSI IP 107.181.176.102 is not permitted to send messages.  
Please contact support if you feel this is in error..

 

(google) Search Results:
107.181.176.102
Your public IP address

Bronze Problem Solver

Re: 421 Error when sending email IP address is not permitted to send messages

Typically this error happens when the IP has been sending a fair bit of spam.  I'm looking into the cause, but I'd expect that to be the reason.  I'll get back to you shortly.


I am a Retired Official Comcast Employee and no longer actively support the Xfinity Forum.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark a post as the Best Answer!
New Poster

Re: 421 Error when sending email IP address is not permitted to send messages

Thanks to whoever first mentioned VPN.  I shut mine down (temporarily) and was able to send.

New Poster

Re: 421 Error when sending email IP address is not permitted to send messages

Hello I am having the same problem. When sending emails in an email program I get the following message "An error occurred while sending mail: The mail server sent an incorrect greeting: resomta-po-11v.sys.comcast.net resomta-po-11v.sys.comcast.net CSI IP 217.156.208.210 is not permitted to send messages. Please contact support if you feel this is in error..". When I send emails from a browers they go through successfully.

Official Employee

Re: 421 Error when sending email IP address is not permitted to send messages

mrfluffy, thanks for posting about your email issues via the third party program. I recommend you reach out to our customer security assurance team to resolve this issue. They are working with folks on this thread but you can also call them here 1-888-565-4329. 


I am an Official Comcast Employee.
Official Employees are from multiple teams within Comcast: CARE, Product, Leadership. We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark the post as Best Answer!
New Poster

Re: 421 Error when sending email IP address is not permitted to send messages

If you have a VPN turn it off and reboot.  I was having the same problem (could recieve emails but not send them).  This worked for me.

Frequent Visitor

Re: 421 Error when sending email IP address is not permitted to send messages

Pretty much as an update, I still have this problem but it has not happened as frequently in the past 6 months.  As a restatement of my problem - with my VPN engaged, outgoing emails are blocked some of the time.  With the VPN turned off, no outgoing emails are blocked, ever.  When I first posted here about a year ago, about 80% of my outgoing emails were blocked.  Note that this was an intermittent problem and that some outgoing emails were sent over the VPN without any issue.  Currently, only about 5% are blocked.  My point is that the problem has not gone away entirely.

 

My guess is that, when you reboot, you are getting a new VPN connection that just happens to be using an IP that is not blocked by the service providers. 

Silver Problem Solver

Re: 421 Error when sending email IP address is not permitted to send messages

Hello all, 

 

@lortoad and @aluminum - Thank you so much for sharing the troubleshooting steps and your findings!


I am a Retired Official Comcast Employee and no longer actively support the Xfinity Forum.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark a post as the Best Answer!
Regular Visitor

Re: 421 Error when sending email IP address is not permitted to send messages

No prob. I always suspect VPN. You have to turn it off for Papa John's 🍕 too.
Silver Problem Solver

Re: 421 Error when sending email IP address is not permitted to send messages

A@ARLibertarian - No pizza with VPN? That's a bad deal


I am a Retired Official Comcast Employee and no longer actively support the Xfinity Forum.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark a post as the Best Answer!
New Poster

Re: 421 Error when sending email IP address is not permitted to send messages

I'm a computer technician with a customer that has an email account from comcast that he's using on a spectrum IP address that is being blocked.  The block goes away every 4-8 hours then it's right back.  Is there any way we can make this permanent? 

 

@CCAntiSpam 

Bronze Problem Solver

Re: 421 Error when sending email IP address is not permitted to send messages

Sending you a PM


I am a Retired Official Comcast Employee and no longer actively support the Xfinity Forum.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark a post as the Best Answer!
Regular Visitor

Re: 421 Error when sending email IP address is not permitted to send messages

Having trouble sending outgoing emails from my Comcast email address on Outlook while on my home WiFi.  Have not problem sending them when NOT on WiFI or when sending while logged into the xFinity website.  Please help.

Bronze Problem Solver

Re: 421 Error when sending email IP address is not permitted to send messages

I'll answer your PM shortly. @Finsta 


I am a Retired Official Comcast Employee and no longer actively support the Xfinity Forum.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark a post as the Best Answer!
New Poster

Re: 421 Error when sending email IP address is not permitted to send messages

Hello, I am having this same issue. This is the error message I receive:

 

421 resomta-po-02v.sys.comcast.net resomta-po-02v.sys.comcast.net Excessive failed authentication, ESMTP server temporarily not available

Bronze Problem Solver

Re: 421 Error when sending email IP address is not permitted to send messages

@skip20101 Sending you a PM with some details to hopefully help resolve this.


I am a Retired Official Comcast Employee and no longer actively support the Xfinity Forum.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark a post as the Best Answer!
New Poster

Re: 421 Error when sending email IP address is not permitted to send messages

I'm having the same problem - internittently can't send Outlook emails from my comcast account. (but I can receive them)  I don't have a VPN, but I do have another, business, account thru a diffrerent server.  It works fine, so I know my problem is not with Outlook itself.  And I can send/receive emails on the Comcast web site.  It looks like Comcast has beenb working on this problem for nearly a year.  Is there any fix?  txterry

 

Bronze Problem Solver

Re: 421 Error when sending email IP address is not permitted to send messages

@txterry Are you getting an error message, or a general timeout?


I am a Retired Official Comcast Employee and no longer actively support the Xfinity Forum.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark a post as the Best Answer!
Regular Visitor

Re: 421 Error when sending email IP address is not permitted to send messages

Hi,

I am a past Comcast member but have moved to Tampa area. I am also receiving the same error on occasion. For some reason it seems to happen betweeen 3 and 7 pm. I can send via the internet and seems like through my android phone. This just started within the last few months before that, for the last year everything was fine. There have been no changes to Spectrum cable box or the wireless Asus router. When we get this message in Outlook the messages sit in the outbox until whatever is happening resolves itself. I am running Outlook 2013 and my wife is running outlook 2016.

No VPN, our phones connect to the same Wi-Fi

Any help would be appreciated  

 

Bronze Problem Solver

Re: 421 Error when sending email IP address is not permitted to send messages

@mrmich I'll respond to your PM, give me a few minutes to do some research.


I am a Retired Official Comcast Employee and no longer actively support the Xfinity Forum.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark a post as the Best Answer!
Regular Visitor

Re: 421 Error when sending email

Hello, I saw on this forum that you could help with this. My email sits in my outbox for hours and then goes out hours later. It seems like a cycle. I saw that the IP address could be blocked from sending out mail and then released every few hours. Could this be the issue? Thank you for your help.

Bronze Problem Solver

Re: 421 Error when sending email

I responded to the PM that @Leopreferred had sent to me.


I am a Retired Official Comcast Employee and no longer actively support the Xfinity Forum.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Mark a post as the Best Answer!