POP, the Post Office Protocol: Generally, email clients that use POP will download email to a local system (e.g. your laptop) and then delete the emails from the remote server.
IMAP, the Internet Message Access Protocol: More flexible than POP. The default is to leave email messages on the remote server until the user explicitly deletes them. IMAP was designed to enable access to email from multiple email clients (e.g., email client on laptop, on desktop, and on phone, simultaneously).
SMTP, the Simple Mail Transfer Protocol: to route and deliver messages.
Check for and install any updates, and then install Postfix and mailx:
sudo dnf check-update sudo dnf -y upgrade sudo systemctl reboot # new kernel update; reboot required sudo dnf -y install postfix mailx
Enable Postfix on startup using systemd, and then start Postfix:
sudo systemctl enable postfix.service sudo systemctl start postfix.service sudo systemctl status postfix.service # check its status
Test the SMTP connection:
telnet localhost 25 ehlo localhost mail from: sean@localhost rcpt to: firstname.lastname@example.org data Subject: this is my first email Hi, What's up? Let me know! - root . quit
mailx on sweb or sised. E.g.:
ssh user@sised mail -s "hello there" other-user