I updated a few months ago, haven't been able to access emails every since.
I get the following on all my accounts:
Timestamp: 12/4/2015 8:59:56 AM Error: An error occurred during a connection to voda25.vodahost25.com:993.
SSL received a weak ephemeral Diffie-Hellman key in Server Key Exchange handshake message.
(Error code: ssl_error_weak_server_ephemeral_dh_key)
Alle svar (1)
The error means your email provider's server is not properly configured and exposes you to the LogJam attack. Thunderbird is trying to prevent that. https://weakdh.org/
As a workaround you can install this add-on. https://addons.mozilla.org/en-US/firefox/addon/disable-dhe/
Note, this will allow you to connect to the server in a secure way, but it doesn't address the underlying problem of the server still being vulnerable.
Check this article if you are having difficulties installing the add-on for Thunderbird. http://xenos-email-notes.simplesite.com/416814616