Register Aliyun DirectMail as SMTP provider for msmtp

msmtprc

# install system package: msmtp-mta
# put this config file at /etc/msmtprc
# find Aliyun DirectMail service at https://aliyun.com/product/directmail

defaults
auth    on
tls     on
tls_trust_file  /etc/ssl/certs/ca-certificates.crt
aliases /etc/msmtp_aliases
logfile ~/.msmtp.log

# aliyun
account aliyun
host smtpdm.aliyun.com
port 465
from root@<MAILDOMAIN>
tls_starttls off
auth login
user root@<MAILDOMAIN>
password <PASSWORD>
maildomain <MAILDOMAIN>
domain <MAILDOMAIN>

account default : aliyun