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Blacklisted Public IP Received From Comcast  


Ari Laquidara
Estimable Member
Joined: 3 years ago
Posts: 154
January 5, 2019 5:47 EST PM  

Hi Mac Geeks,

This isn't actually a Mac-specific question, but wondered if someone here knew a way to resolve. I got a call today from someone whose public IP address (assigned to them via DHCP from Comcast) has been blacklisted. Meaning he can't send or receive email when sending from his home network. He has spent hours on the phone with Comcast seeing if they can assign him a new, non-blacklisted address, however they weren't able to do so. Is there a way to resolve? His public IP is, and if you check it out on MX Toolbox you will see he is indeed blacklisted. Thoughts or suggestions?


Active Member
Joined: 2 years ago
Posts: 10
January 6, 2019 10:17 EST PM  

For the short term, would a VPN service be a work around while he's trying to rectify the situation? I use TunnelBear on my iPhone at rare times and believe its free for limited use.


Ari Laquidara
Estimable Member
Joined: 3 years ago
Posts: 154
January 6, 2019 10:20 EST PM  

@fixedon66, thanks for your reply. I wonder if this could be done through his router, by setting up an outgoing VPN (if it can do that -- I think he might have a Comcast gateway, which I don't believe can be set up with outgoing VPN). @davehamilton, any thoughts?


Graham McKay
Reputable Member
Joined: 4 years ago
Posts: 304
January 8, 2019 7:34 EST AM  

Blacklisted IP addresses of the clients of ISPs is a common problem and most ISPs have somebody, or a procedure at least, for submitting de-list requests to the blacklist services. So usually it should resolve within 48 hours? (Unless there really is outgoing spam from that address?)

A new sponsor of the show ExpressVPN (supposedly) allows outgoing connections to be directed via VPN on an app by app basis. So installing this would allow one to specify that just the mail app use the VPN connection.

The other short term solution I give to clients who have been IP blocked from services is to use a hotspot connection to their phone while accessing those services - coz that will give a different allocated external IPv4 address.

DD-WRT flashed routers allow you to install outgoing VPN profiles - I have one configured for connecting my SkyTV box to an IPVanish VPN server in the UK. And I can connect other devices via wifi if I need them to be "in the UK". I used it while in Switzerland and it sat on the inside of my VDSL router - effectively doing double NAT for those devices. That's a bit OTT for a temporary problem.

PS. I also use MX Toolbox for various email troubleshooting 🙂