Mail

General

Your mail server's IP must be known to your buddy's email client
MAIL TRANSFER AGENT: Your mailserver listens on a particular port, accept connection from the other persons. Your mailserver will decide which mailbox the email will be delivered to, manage email queue, etc
IMAP/POP3 SERVER: Client will connect to either imap or pop3 server in order to READ the mail
WEBMAIL SERVER: Website-based (clientless) access to email inbox
Look into using mailcow via docker.

MTA can be relay-only ("send only")
- Send-only MTA forwards my emails to another server, typically the SMTP server of your ISP.
- E.g., nullmailer, msmtp, and sSMPT
Full-fledged MTA, a.k.a., mailhub
- E.g., postfix, sendmail, exim
SMTP = Simple Mail Transfer Protocol
mnemonic: Sending Mail To People
SMTP is like a mailman
A set of commands that authenticates and directs the transfer of email

Email client sends your message to the SMTP server, e.g., smtp.gmail.com
My SMTP server will send my mail to the recipient's email server. There my email will stay until the recipient logs into their email server and downloads my message via IMAP or POP3, or view the email on the server by using webmail.

SMTP uses the TCP protocol. TCP guarantees email delivery, assuming the email address exists and is correct, otherwise you get a mail delivery error.

echo “This will go into the body of the mail.” | mail -s “Hello world” you@youremailid.com
mail -s “Hello world” you@youremailid.com < /home/calvin/application.log
- echo “Welcome to the world of Calvin n Hobbes” | mail -s “Hello world” calvin@cnh.com -c hobbes@cnh.com -b susie.derkins@cnh.com
echo "Here is the dump file. Only 1.6 megs." | mutt -a iicbu.dmp -s "iicbu svn dmp file" lhotskyb@grc.nia.nih.gov christopher.coletta@nih.gov