As of product update 2020.7, 2021.4, and 2022.1 which was released in December 2021. Sage 300 is not compliant with TLS 1.2 for SMTP.
Sage 300 development will release compliance with TLS 1.2 in March/April release, which will be product update 2020.8, 2021.4, and 2022.2.