Can't send emails via Thunderbird
I have been using Thunderbird for years now. Just last week I started not being able to send emails- incoming works fine, just not outgoing. I think it coincides with an update it did from version 68.12.1 (20200929010218) to version 78.4.0 (20201019003438). Since then, I've been getting this error message: Sending of the message failed. Peer using unsupported version of security protocol. The configuration relating to mail.xxxxxx.xxx.xx must be corrected. I'm not hugely technical. Does anyone have some easy steps to fix this? Thanks