MSMSTP

apt install msmtp

root@bananapir2:~# msmtp --configure mujmail@gmail.com
# - copy this to your configuration file /root/.msmtprc
# - add your password to the key ring:
#   secret-tool store --label=msmtp host smtp.gmail.com service smtp user mujmail
account mujmail@gmail.com
host smtp.gmail.com
port 587
tls on
tls_starttls on
auth on
user mujmail
from mujmail@gmail.com