Famous email server.
The sendmail command is a famous Mail Transfer Agent (MTA), commonly known as an email server. It is based on the standard Simple Mail Transfer Protocol (SMTP).
sendmail(options)
-bd: Run as a daemon.
-bD: Run in the foreground.
-bi: Initialize the alias database.
-bm: Send email in the conventional way.
-bp: Display the mail transfer queue.
-C: Specify a configuration file.
-D: Save debugging output to a log file instead of displaying it on the standard output.
-F: Specify the sender's full name.
-n: Disable the mail alias feature.
-f: Specify the sender's name.
-q: Set the interval for processing mail in the queue.