1786181 - Cannot digitally sign this message, because you haven't yet configured end-to-end encryption

Status: RESOLVED DUPLICATE of bug 1783909

(Thunderbird :: Message Compose Window, defect)

Description

[Colin Finck]

Steps to reproduce:

I have two mail accounts in Thunderbird, one with configured OpenPGP and digitally signing enabled by default (Account A) and one without any end-to-end encryption (Account B).
While browsing through the inbox of Account A, I click "Compose" to compose a new message. I then decide that I want to send it from Account B, so I change the sender address in the dropdown of the Compose window.
When I'm done composing the message, I click "Send".

Actual results:

I get an error message:

"Cannot digitally sign this message, because you haven't yet configured end-to-end encryption for <Account B>."

Expected results:

The message should be sent without any error message.

This happens, because the Security > Digitally Sign Message checkbox is ticked when composing the message from the inbox of Account A.
It is kept in this state when switching the sender to Account B.
However, all Security settings are greyed out after switching the sender to Account B (because end-to-end encryption is not configured for Account B).

The only way I can currently work around this is switching the sender back to Account A, unticking the Security > Digitally Sign Message checkbox, and switching the sender to Account B again. This is non-intuitive though.

My suggestion is that Thunderbird reevaluates the end-to-end encryption settings every time when switching senders, and adjusts the checkboxes in the Security menu accordingly.
When I switch to Account B, Security > Digitally Sign Message should be unticked.
When I switch back to Account A, it should be ticked again.