Comcast and VPN's

[shotcaller6]

Anyone using Comcast and having their emails blocked? I have to disconnect from my VPN (Express VPN) in order to send email.

Comcast claims there is nothing being done on their end.

[tomk556]

What email service and protocol?

Weird things can happen with VPNs. I had one that would block google/gmail for some reason, but not duckduckgo...

[shotcaller6]

I'm using Mozillia's Thunderbird email. I am receiving emails ok, I just can't send them unless I disconnect from the VPN.

This is a partial wording of the message, resomta-po-13v.sys.comcast.net

When I searched that phrase on DuckDuckGo I found a whole lot of people with the same issues, Comcast and VPN's seems to be the defining problem.

[Fizz]

It's more likely your SMTP server isn't accepting communication from your VPN provider's network as an anti-spam/security policy.

Not all VPNs work the same. Some may only route select traffic across the VPN, others route all traffic.

Comcast is correct. They have no control over what happens when you connect to a VPN. If the email traffic occurs over the VPN, Comcast has no idea. That's rather the point of the VPN....

[Librarian]

It's more likely your SMTP server isn't accepting communication from your VPN provider's network as an anti-spam/security policy.

Not all VPNs work the same. Some may only route select traffic across the VPN, others route all traffic.

Comcast is correct. They have no control over what happens when you connect to a VPN. If the email traffic occurs over the VPN, Comcast has no idea. That's rather the point of the VPN....

I have similar experience; some VPN server nodes will not accept my email, some will. Some web sites just won't work right through some VPN nodes. Some sites won't work at all - I've noticed a number of government sites refuse connections, while my 'ordinary' service works fine.

Sometimes the VPN node just silently goes down and nothing seems to work. Sometimes it's horribly busy and slow.

But I've had to use a bunch of hotel and coffee shop 'free' wifi recently, and I really prefer my VPN connection in those places.

[shotcaller6]

It's more likely your SMTP server isn't accepting communication from your VPN provider's network as an anti-spam/security policy.

Not all VPNs work the same. Some may only route select traffic across the VPN, others route all traffic.

Comcast is correct. They have no control over what happens when you connect to a VPN. If the email traffic occurs over the VPN, Comcast has no idea. That's rather the point of the VPN....

I think you nailed it this is the error message.

An error occurred while sending mail: The mail server sent an incorrect greeting: resomta-po-06v.sys.comcast.net resomta-po-06v.sys.comcast.net CSI IP 104.143.92.48 is not permitted to send messages. Please contact support if you feel this is in error..

I will contact expressvpn support about this issue.

Librarian is right, I feel naked and exposed without the vpn.

[Fizz]

I think you nailed it this is the error message.

An error occurred while sending mail: The mail server sent an incorrect greeting: resomta-po-06v.sys.comcast.net resomta-po-06v.sys.comcast.net CSI IP 104.143.92.48 is not permitted to send messages. Please contact support if you feel this is in error..

I will contact expressvpn support about this issue.

Librarian is right, I feel naked and exposed without the vpn.

https://search.arin.net/rdap/?query=104.143.92.48

Yeah, that IP belongs to a readily identifiable VPN provider network. I'm not sure why or how the forward/reverse lookup of the DNS/IP is a mismatch.

resomta-po-06v.sys.comcast.net resolves 96.114.154.230 - This host belongs to Comcast's network.

104.143.92.48 - Belongs to your VPN provider's network, and consequently cannot reverse lookup to your provider's network. There's either a wholesale ban on the VPN provider's network, by your email provider, or they don't like that there's no rDNS

[Fizz]

I have similar experience; some VPN server nodes will not accept my email, some will. Some web sites just won't work right through some VPN nodes. Some sites won't work at all - I've noticed a number of government sites refuse connections, while my 'ordinary' service works fine.

Sometimes the VPN node just silently goes down and nothing seems to work. Sometimes it's horribly busy and slow.

But I've had to use a bunch of hotel and coffee shop 'free' wifi recently, and I really prefer my VPN connection in those places.

There's a good chance that the VPN doesn't do what you think it does.

You really have to to see if the VPN is a tunnel-all VPN, or select traffic like web only. Tunnel all VPNs will direct DNS requests, games, OS updates, etc. over the VPN. Some others only direct HTTP(s) traffic over the tunnel.

The 'privacy' afforded by anonymizing your public IP is overstated by most VPN providers to FUD you into subscribing. There are very few actual 'no-log' VPN providers out there. If you pay them, they keep logs. If government really wanted to know, they could subpoena records from all in the chain.

On public wifi there is some use. However, unless the VPN blocks traffic until its connected, connecting to wifi generally means there's a window before the VPN is established that DNS requests, websites, background services, all connect over the normal wifi connection. Also, unless the VPN forcibly terminates these connections, you end up with connections that are partially VPN'ed and others plain.

Most anything anyone cares about is encrypted already. If you have OLD school SMTP/POP setup without encryption, you could be leaking your email password all over the place and VPN *might* help, but the real solution is to not do stupid crap like that. In this scenario, you're not leaking your email/pass to the network/ISP, but everyone upstream from the VPN provider.

[shotcaller6]

Express VPN is supposed to route all traffic thru a tunnel and no logs kept, so far I have not heard anything different but then again I have been lied to before, Congress comes to mind.

I am currently able to send emails again, it took 5 servers to get one that works, for now anyway, so if it happens again I know what to do. I actually have had no problems other than this email thing.

I use an old Linksys wrt 1200ac router and flashed their firmware and run everything through that secondary router and don't use any VPN Apps. DNS server check shows no leaks but how does a guy check too be sure everything is above board?


EDIT: This link provides an extensive review of ExpressVPN in case anybody was curious. https://www.techradar.com/reviews/expressvpn

[Librarian]

There's a good chance that the VPN doesn't do what you think it does.

You really have to to see if the VPN is a tunnel-all VPN, or select traffic like web only. Tunnel all VPNs will direct DNS requests, games, OS updates, etc. over the VPN. Some others only direct HTTP(s) traffic over the tunnel.
.

I use Nord.

[Robotron2k84]

What you’ve stumbled onto is a PBL, policy black list, for the exit node of your VPN. I.e. it falls in an IP range administratively blocked by services because others abused the VPN to anonymously send spam.

There is no getting around it.

Set up your mail correctly, using SMTP submission on port 465/587, depending on the server and that already forces encryption between server and client. You don’t need a VPN in that case. Remember, you are authenticating with a username and password to the SMTP server, having a random IP doesn’t add any extra security, you aren’t anonymous, should any authority request logs from your email provider. Another reason I run my own.

If all you are concerned with is being on-the-go and having a tunnel handy on untrusted networks, why not use your home internet connection and router as a VPN gateway? Most home routers can be VPN hosts for boomerang routes and that solves the transit issue. People that trust VPN services for anything more than getting around content restrictions for media are simply asking for trouble.

[Robotron2k84]

Trouble indeed, NordVPN hacked:

https://techcrunch.com/2019/10/21/nordvpn-confirms-it-was-hacked/