Cannot connect to gmail or a hostinger email acount. Have tried all the online fixes. Nick
The accounts seem to be accepted then say server cannot be found. Have tried config editor change, cache on my firefox account etc. etc Tried forwarding gmail to my working email account but Thunderbird says 'authentification failure' Have tried various online fixes Spent at least 2 hours trying to get this fixed. It seems to be a common occurence but all the suggested fixes do not work.
Opaite Mbohovái (1)
Seriously "all the suggested fixes do not work." leave this open to a dispute. It says nothing really, except express you are frustrated. I have no real idea what you have actually done, so when I suggest things you have already done your frustration just increases.
So I will have a lash and hopefully you can refine the what you have done.
When you add an account, especially a gmail one the new account wizard will tell you that the settings were found. If that is the case your firewall is not blocking Thunderbirds access to the internet. If however settings are not found for gmail a firewall issue is almost certain. GMail has settings on the web to be found, so we can be sure of that one at least. If your mail provider is listed here https://autoconfig.thunderbird.net/v1.1/ then there are settings to be found online.
Next is to ensure that cookies are enabled in Thunderbird. Some "security" software either recommends they be disabled or actually disables them for you. However oAuth authentications which Yahoo and Gmail are insisting on requires cookies.
"server not found" sounds like a DNS problem, when looking up the servers IP address. This can have many causes, from security software to bad DNS servers provided by an ISP. I have even heard of software firewalls that block DNS queries by application, so you have to explicitly allow DNS access for each application.
Step 1: access the config editor to access Thunderbird's hidden preferences. You will need to enable and modify three settings.
Step 2: The first setting is network.trr.mode. This turns on DoH support. This setting supports four values:
0 - Default value in standard Firefox installations (currently is 5, which means DoH is disabled) 1 - DoH is enabled, but Firefox picks if it uses DoH or regular DNS based on which returns faster query responses 2 - DoH is enabled, and regular DNS works as a backup 3 - DoH is enabled, and regular DNS is disabled 5 - DoH is disabled
Step 3: The second setting that needs to be modified is network.trr.uri. This is the URL of the DoH-compatible DNS server where Thunderbird will send DoH DNS queries. By default, Thunderbird uses Cloudflare's DoH service located at https://mozilla.cloudflare-dns.com/dns-query. While you can modify this setting, for the purposes of this test there is little point. If you are in the US you will be using it for Firefox anyway.
That is a start, see how that goes.