Send an Email to Undisclosed Recipients from Gmail

Whenever you want to send mail to a mass of people, you generally include all the email IDs in the TO: field of your email client. So, when a recipient receives this mail, he/she can see who all are the other recipients. But what if you do not wish to disclose recipients email addresses? Here is a trick to keep recipients' addresses undisclosed. I have used Gmail to test this trick, but it works with all other email clients.

 

To address a message in Gmail so that it goes to "undisclosed recipients" but arrives in all the real recipient's inboxes:

1. Click Compose Mail to start a new message.

2. Type your own email address  OR "Undisclosed Recipients <your email address>" (without double-quotes) in the To: field. 

3. Click Add Bcc.

4. Type the email addresses of all the intended recipients in the Bcc: field. Make sure you separate addresses by comma. If you write to same group of recipients frequently, you can make a mailing list.

5. Now type the subject and message, and finally click Send button.

 

That's all !!

CAPTCHA

The word CAPTCHA stands for "Completely Automated Public Turing test to tell Computers and Humans Apart".
CAPTCHA is a type of challenge-response test used in computing to determine whether a user is being imitated by a computer. The process involves one computer (a server) asking a user to complete a simple test which the computer is able to generate and grade. Because other computers are unable to solve the CAPTCHA, any user entering a correct solution is presumed to be human. A common type of CAPTCHA requires that the user type the letters displayed in a distorted image, sometimes with the addition of an obscured sequence of letters or digits that appears on the screen.

A CAPTCHA is sometimes described as a reverse Turing test, because it is administered by a machine and targeted to a human, in contrast to the standard Turing test that is typically administered by a human and targeted to a machine.

Currently, reCAPTCHA is recommended as the official CAPTCHA implementation by the original CAPTCHA creators.

Applications:
CAPTCHAs are used to prevent automated software from performing actions which degrade the quality of service of a given system, whether due to abuse or resource expenditure. Although CAPTCHAs are most often deployed as a response to encroachment by commercial interests, the notion that they exist to stop only spammers is mistaken. CAPTCHAs can be deployed to protect systems vulnerable to e-mail spam, such as the webmail services of Gmail (there is also a claim that the Gmail CAPTCHA has been compromised), Hotmail, and Yahoo!. CAPTCHAs have also found active use in stopping automated posting to blogs, forums and wikis, whether as a result of commercial promotion, or harassment and vandalism. CAPTCHAs also serve an important function in rate limiting, as automated usage of a service might be desirable until such usage is done in excess, and to the detriment of human users. In such a case, a CAPTCHA can enforce automated usage policies as set by the administrator when certain usage metrics exceed a given threshold. The article rating systems used by many news web sites are another example of an online facility vulnerable to manipulation by automated software.