[Users] Claws Mail Can't Connect to Internet With Specific Internet Connection

[Richard]

> Date: Tuesday, October 11, 2022 20:45:31 +0600
> From: Dustin Miller <dustbiz at gmail.com>
>
> On Tue, 11 Oct 2022 15:47:39 +0200
> Paul Rolland <rol at witbe.net> wrote:
> 
>> 
>> You can use openssl to test (exemple with POP3):
>> 
>> 187 [15:44] rol at riri:~> openssl s_client -host riri.xxx.xxx -port
>> 995
>> 
> DM: Thanks, Paul R, it's quite helpful to know about this method of
> testing. With the 'okay' connection and using 'pop.gmail.com', I got
> what looked like expected output without any noticeable errors. With
> the 'problem' connection, I got no output at all. I also tried
> 'smtp.gmail.com' with port 587 on the 'problem' connection; once
> again, no output (on the 'okay' connection it gives output w/o any
> errors). (BTW, previously I had also tried unchecking the box
> related to non-blocking TLS in the Claws settings, but that didn't
> help either.)
> 
> DM: I'm not sure what to gather from these results. Does it mean
> that the problem is likely something local on my system before
> there is any connection to the internet? Or is it still possible
> that it could be an issue outside of my system (local network
> device settings, or ISP settings)? Thanks again, ---Dustin

It sounds like you may have a routing and/or DNS issue. Try using
traceroute and dig to see what you get.