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Outlook for my Comcast account does not work when on another ISP.

misfitmojo
New Poster

Outlook for my Comcast account does not work when on another ISP.

My Outlook is configured properly for access to my Comcast email, as I can access it without error at home or on another Comcast serviced network. The issue is that when I am connected to networks serviced by other ISPs I cannot send emails through Outlook. I've called support, they haven't given me an answer and never come through on their promises to call back when they want to research the problem.

BruceW
Gold Problem Solver

Re: Outlook for my Comcast account does not work when on another ISP.


@misfitmojo wrote: ... I cannot send emails through Outlook. ...

"Cannot send" doesn't give us much to go on. What happens when you try? Any error messages? The more details you can provide, the better.

 

misfitmojo
New Poster

Re: Outlook for my Comcast account does not work when on another ISP.

I believe the SMTP server gives a message about an unauthorized IP. I can't recreate the error when I'm at home since it only happens when I'm not on a Comcast connection.

BruceW
Gold Problem Solver

Re: Outlook for my Comcast account does not work when on another ISP.


@misfitmojo wrote: I believe the SMTP server gives a message about an unauthorized IP. ...

If the message looks something like "421 resomta.?????, CSI {ISP} {IP address} is not permitted to send messages" ...

 

CSI in the error message means the listed IP has been flagged by Cloudmark Sender Intelligence, an IP reputation service, as not trustworthy. Typically the IP has been associated with spam or some other form of abuse. Please see https://forums.xfinity.com/t5/Email-Web-Browsing/Can-t-Send-Emails-from-PC-or-Phone-App/m-p/3355422#... for a discussion by employee @ComcastCSAEmail of how Comcast uses CSI.

 

misfitmojo
New Poster

Re: Outlook for my Comcast account does not work when on another ISP.

Yeah, that's the error I'm getting. So basically you'd need to remediate every ISP that gets flagged but you don't know who they are. That's pretty ridiculous.