mail

The mail program will list mail that has been sent. Select the last mail which you just sent by typing the number corresponding to the mail. You will see something similar to this:

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From This e-mail address is being protected from spambots. You need JavaScript enabled to view it Mon Mar 28 03:19:17 2005

X-Original-To: mike

Delivered-To: This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Date: Mon, 28 Mar 2005 03:19:17 -0700 (MST)

From: This e-mail address is being protected from spambots. You need JavaScript enabled to view it (mike)

To: undisclosed-recipients:;

this is a test of the sendmail program

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The text that you see above your line of text for the mail is called the header. The header is a portion that is added by sendmail. The body, which is separated from the header by a blank line, is the content of your email.

The header format is based on a word which is followed by a colon. The word establishes the content of the line that follows. For example, Delivered-To: describes the user the mail was actually delivered to.

The Subject: of the header is a optional feature. The Subject: can be added by editing your original file and adding:

Subject: Test

###########################################

From This e-mail address is being protected from spambots. You need JavaScript enabled to view it Mon Mar 28 04:02:15 2005

X-Original-To: mike

Delivered-To: This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Subject: test

Date: Mon, 28 Mar 2005 04:02:15 -0700 (MST)

From: This e-mail address is being protected from spambots. You need JavaScript enabled to view it (mike)

To: undisclosed-recipients:;

this is a test of the sendmail program

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The Subject: line is now viewable in the header since you manually added it to your file like an email program does.

Try to add two Subject: lines...notice the result.

###########################################

...snip

Subject: test

Subject: new test

Date: Mon, 28 Mar 2005 04:12:06 -0700 (MST)

..snip

###########################################

Sendmail is looking for a format string, text + : which it determines how it will be used in the header. Try to add a line for FROM:

Add this line to your file:

From: Aliens

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From This e-mail address is being protected from spambots. You need JavaScript enabled to view it Mon Mar 28 04:02:15 2005

X-Original-To: mike

Delivered-To: This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Subject: test

From: This e-mail address is being protected from spambots. You need JavaScript enabled to view it

###########################################

Notice that the program interprets the From: Aliens to be a header line even though a line has already been added by sendmail for the real person who sent the message. This gives you some idea about how spammers will manipulate the header to try to fool recipients about the real originator of the message.

Understanding Header Files

9.6. Mail Delivery Agents