There are three main parts of the Unix E-mail system:
| Part | What It Does | Examples |
|---|---|---|
| Mail User Agent (MUA) | The MUA is the program which the user uses to read and send e-mail. It reads incoming messages that have been delivered to the user's mailbox, and passes outgoing messages to an MTA for sending. | elm, pine, mutt |
| Mail Transfer Agent (MTA) | The MTA basicly acts as a "mail router". It accepts a message passed to it by either an MUA or another MTA, decides based upon the message header which delivery method it should use, and then passes the message to the appropriate MDA for that delivery method. | sendmail, postfix, qmail |
| Mail Delivery Agent (MDA) | The MDA accepts a piece of mail from an MTA and performs the actual delivery. | mail.local, procmail |
mail - send email without attachment
mail -s subject it@bangtech.com < mymailbody.txt
mutt - send email with attachment
mutt -s subject it@bangtech.com -a /tmp/attachment.txt < mymailbody.txt
Quick - send email test with subject only
echo "subject:hello" | /usr/lib/sendmail -v it@bangtech.com