This article covers the Complete guide for setting up a mail server using Postfix, Dovecot & SquirrelMail. 

Linux mail command Options:

• -a, --append=HEADER: VALUE: Append given header to the message being sent.
• -e, --exist: Return true if mail exists.
• -E, --exec=COMMAND: Execute COMMAND.
• -f, --file[=URL]: Operate on given mailbox URL. The default mailbox is ~/mbox.
• -F, --byname: Save messages according to sender.
• -H, --headers: Write a header summary and exit.
• -i, --ignore: Ignore interrupts.
• -n, --norc: Do not read the system mailrc file.
• -N, --nosum: Do not display initial header summary.
• -p, --print: Print all mail to standard output.
• -q, --quit: Cause interrupts to terminate program.
• -r, --read: Same as -p
• -s, --subject=SUBJ: Send a message with a subject of SUBJ.
• -t, --to: Precede message by a list of addresses.
• -u, --user=USER: Operate on USER's mailbox.
• --license: Print license and exit.
• --external-locker=PATH: Set full path of the external locker program
• --lock-expire-timeout=SECONDS: Number of seconds after which the lock expires.
• --lock-flags=FLAGS: Default locker flags (E=external, R=retry, T=time, P=pid)
• --lock-retry-count=NUMBER: Set the maximum number of times to retry acquiring the lockfile.
• --lock-retry-timeout=SECONDS: Set timeout for acquiring the lockfile.
• -m, --mail-spool=URL: Use specified URL as a mailspool directory.
• --mailbox-type=PROTO: Default mailbox type to use.
• --tls[=BOOL]: Enable TLS support.
• -?, --help: Display a help message and exit.
• --usage: Display a short usage message and exit.
• -V, --version: Display program version and exit.