Using Thunderbird Mail through BT what do I set in the SMTP box for outgoing Mail?

[JohnOYork]

I have been using the Thunderbird Mail program for a few years but since 3 ministrokes I've been making mistakes and been unable to correct them.

I use 3 EMail Addresses, and all have been receiving OK, but suddenly I could not SEND any mail from any of the 3 ????????
I believe I need to check the setting for Outgoing Mail - but what do I put in the SMTP Box ???

I'm trying to sell my Car as I'm not now allowed to drive (and my wife is an invalid) but with no means of sending Mail simply I'm getting all screwed up and unable to think my way out of the pickle. ANY HELP WELCOME - PLEASE

[Mod edit - removed email address - please do not post personal details in the community]

[imjolly]

https://www.bt.com/help/email/manage-email-account/manual-settings/what-are-the-settings-for-outgoin... 

this BT email settings

Please delete your email addresss as this is public forum and you may get more spam than you can handle

[gg30340]

Are you presently a BT Broadband customer or are you paying for your email through a BT Premium email account?

If neither of the above your email account may have been downgraded to a BTMail Basic account which can not be used with an email client

See link

https://www.bt.com/help/email/bt-email-products

Have you checked to see if you can send and receive emails using your BTMail accounts with a web browser such as Chrome or Microsoft Edge?