I don't know if this feature has already been proposed, I searched for information about it but found nothing.
A few days ago I was configuring Thunderbird to be used with an email account from a server at the company where I work. When these accounts are configured in Outlook, Outlook connects to the IMAP/POP server as part of the connection test and reads the mailbox. input, but also sends a test email via SMTP, if both actions occur the email account is configured correctly.
This does not happen in Thunderbird because it does not send any test email, it only tests if it can connect to the SMTP server but it does not send anything, the problem was that that email account had a problem with the SMTP server (it was blocked by the provider) and Thunderbird never noticed the problem (something it did in Outlook) until I tried to send an email and it was not possible.
Would it be possible to implement something like this in Thunderbird? Send a test email via SMTP when configuring the email account, perhaps as something optional but I see that it is very practical. Thank you.