Connectivity
Connectivity and managing Your Comcast Business network
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Occasional Visitor

Port 25 and 465 not open...no traffic

How do I get port 25 and/or 465 open on my Business account?  SMTP mail traffic not going through.

 

Hao

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Trusted Forum Contributor

Re: Port 25 and 465 not open...no traffic

So occasionally, Comcast will block inbound TCP port 25, but if you call in and/or IM one of the mods on this forum, they can have that block removed. However, I don't know of any circumstance where they block port 465... here is the official list of blocked ports:

 

http://businesshelp.comcast.com/help-and-support/internet/ports-blocked-by-business-class-internet/

 

So you might have some firewall issues on your end. Mind telling us more about your network? (which model of gateway, which routers/firewalls you have if any, what sort of SMTP server, etc.)

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Re: Port 25 and 465 not open...no traffic

Had Comcast business account and mail was working fine with a Comcast cable modem.  Moved business account home where I was using the Motorola SB6121 cable modem.  Now mail is not working...everything behind cable modem is idenitcal as previous.  

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Trusted Forum Contributor

Re: Port 25 and 465 not open...no traffic

Hello HaoT and welcome,

 

You should register your Business Class Portal account and use you DNS info mail addresses provided within that link.

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