Solved E-mail server - connection refused on Vivaldi mail only. Works fine on VPN?? Help!

[wheeljack]

I have been using Vivaldi mail for some time now, accessing it through the web, Outlook on Windows, K9 on Android, and Evolution on Linux. I also have a pair of Asus RT-AX92Us using Merlin firmware as a mesh, and have those setup to use secure DNS etc. Two things changed recently - I had a firmware update for the router(s) and I changed provider to Virgin Media. Ever since then my troubles with accessing Vivaldi mail began.

I started getting server and connection issues with Vivaldi, whereas my other email accounts had no issues. I reset the app password and main password for Vivaldi with no change. K9 wasn't affected throughout this, that seems to have worked consistently (mobile network and the asus wifi), but all the desktop clients started to struggle (all on same pc, so same network card). Tried on wifi and disabled Ethernet and still having problems. Weirdly Outlook would connect SOMETIMES but then start being problematic again minutes later. I then tried connecting to my VPN and once connected all my problems went away. ALL email clients started working normally again.

So after checking TCP/IP config on Windows/Linux and not finding anything there, I then went into the router config. I did ponder that maybe my secure DNS settings may be causing issues - but why now when they have worked fine before? Changed those to different settings with nothing working until I turned everything off and just used the standard DNS provided by VirginMedia. Up to now it appears to be fine, although I haven't booted to windows yet but I expect that will work also.

Anyone got any advice as to what settings I can use for secure DNS that aren't going to cause me issues? And maybe explain why these settings worked before?

As I type this I've just thought - is it that VM don't support non standard DNS requests? But if that was the case why would it not affect anything other than Vivaldi mail servers?

Help or insight into this would be appreciated as it's driving me crazy.

Note: When I had my original DNS settings setup in the Asus router, I was using Quad9. I then tried Cloudflare, before then undoing all the changes and just using the standard DNS through Virgin Media. I can't remember the exact settings I had now, but I have attached a screenshot of roughly what it was. Just above you can specify a DNS server to use for normal DNS (so Quad9 and Cloudflare are there too and I originally had it all set to Quad9 servers).

[edwardp]

@wheeljack Change the TLS Hostname for both entries to one.one.one.one and see if that works.

On Android, cloudflare-dns.com does not work for the Private DNS setting (unable to connect), but it will connect to and use one.one.one.one, which is the hostname for both of those IP addresses.

Going to https://1.1.1.1/help afterwards, shows it is using DNS over HTTPS (DoH) as well as DNS over TLS (DoT).

Hope this helps.

[wheeljack]

@edwardp Thanks for the reply. There have however been some developments

[wheeljack]

So, I logged on to my PC today to find I have the same issue again. Connect to VPN - no errors with connecting to Vivaldi mail.
Normal connection - connection refused. Evolution on Linux.

And this is with normal DNS, and nothing untoward with the network setup. I will come back and edit this shortly, as i need to boot into Windows and see whats happening there with Outlook.

Ok, so Outlook worked absolutely fine. I then went to check phones and K-9 Mail was asking for password (my fault - when I updated password I forgot to update K9 Mail settings) so put that in - failed to connect! So continued anyway and updated password on the SMTP server settings and then refreshed the inbox. Two attempts, then suddenly new email came in.

Checked Samsung mail, that was fine. A friend was here with his Mac, so he set me up a user account on it temporarily and I tried adding Vivaldi to Mac Mail - and I thought Outlooks new mail setup was bad....so managed to get Mac mail to work using standard ports and starttls as it would not work with the more secure settings. No connections refused on here, just authentication issues until I changed ports to standard.

Went back to Evolution - all working again!

I do wonder if I've created a rod for my own back here - whilst switching between devices and having logins updated etc is it possible that Vivaldi server is locking me out temporarily causing the connection refused error? I am sharing one app password between these devices too so I wonder if thats causing an issue?

I will try creating an app password for the desktop (as I'd only ever have one email app open at a time with multiboot) and one for the mobiles to use and see how that goes.

[wheeljack]

Ok, so marked EdwardP reply as solution, as that would likely resolve any connection issues when using DoT, which I will revisit soon.

Mainly I believe this may have been user error on my part - a mix of changing the main Vivaldi password then updating app password and setting up multiple devices and probably locking myself out here and there.

I removed Vivaldi email account from all my devices, then logged into my account and created three new separate app passwords.
One for Linux/Mac, one for Windows, and one for Mobile.

I then re-added the account using the correct app password for each device and so far so good.

@edwardp Thanks for your help

[edwardp]

@wheeljack You're welcome.