Sendmail

cat << EOF | sendmail -t 
Sender: [email protected]
From: Sender <[email protected]>
Reply-To: Sender <[email protected]>
To: To <[email protected]>
CC: Cc <[email protected]>
Disposition-Notification-To: [email protected]
Subject: Generic Subject

Generic Body
EOF

Python 3.9

export ENV_EMAIL_SUBJECT='Subject for Debug Email';\
export ENV_EMAIL_SENDER='[email protected]';\
export ENV_EMAIL_FROM='[email protected]';\
export ENV_EMAIL_BODY='Body for Debug Email';\
export ENV_EMAIL_TO='[email protected]';\
\
export ENV_SMTP_USER='[email protected]';\
export ENV_SMTP_HOST='smtp.chorke.org.bd';\
export ENV_SMTP_PASS='p@$$w0rd';\
export ENV_SMTP_PORT='587';\
export ENV_SMTP_DBUG='1';\
export ENV_SMTP_TTLS='1';\
(curl -s 'https://cdn.chorke.org/exec/cli/python/finology/commons/sendmail.py.txt')|python

Knowledge

/usr/sbin/sendmail -Am -v -t < filename.eml
/usr/sbin/sendmail -v -t < filename.eml
/usr/sbin/sendmail -t < filename.eml

launch interpreter by magic header or env
1. Python 3.9: #!/usr/bin/env python3.9
2. Python 2.6: #!/usr/bin/env python2.6
3. TS Node   : #!/usr/bin/env ts-node
4. Python    : #!/usr/bin/env python
5. NodeJS    : #!/usr/bin/env node
6. Ruby      : #!/usr/bin/env ruby
7. Perl      : #!/usr/bin/env perl
8. PHP       : #!/usr/bin/env php
9. GO        : #!/usr/bin/env go run

#resolve mail server
nslookup
: '
Default Server:  www0.dev.chorke.org
Address:  10.20.13.100

> set type=mx
> chorke.org
Server:  www0.dev.chorke.org
Address:  10.20.13.100

Non-authoritative answer:
chorke.org      MX preference = 0, mail exchanger = mail.chorke.org
> exit
'

References

Why Python script start with #!/usr/bin/env python? Configuring SendMail to use username and password Configure sendmail for relaying mail over port 587 Capture debug output from Python smtplib Setup and test SMTP AUTH within Sendmail Sending mail from a Bash shell script Sending a mail from a shell script Reply-To header to send emails Sendmail Attachment Python Send Email

SMTP AUTH extension not supported by server Python access environment variables Run remote Python script via curl