check-if-email-exists

Check if an email address exists before sending the email. Uses Telnet.

I have created this fork from https://github.com/reacherhq/check-if-email-exists because it is completely sufficient and simple for my areas of application, according to the KISS principle ;).

Why?

Many online services (https://hunter.io, http://verify-email.org, http://email-checker.net) offer this service for a paid fee. Here is an open-source alternative to those tools.

Usage

Make sure you have Telnet installed.

./checkEmail.sh you@domain.com

Outputs true if email exists, false if it doesn't.

Some mail providers validate sender's mail address before respond, so you should give a valid mail address as sender's mail.

You can do this by one of the following methods:

export SENDER=vaild_sender@domain.com
./checkEmail.sh you@domain.com

or

./checkEmail.sh you@domain.com vaild_sender@domain.com

Notes

This is really a draft version of the tool, for my personal uses. If someone wants to improve it (and it's easy), please submit a PR. The code is really easy, but needs some improvement to be deliverable to the public.

The main Bash script (checkEmail.sh) calls an expect script (expectTelnet.sh) to make a Telnet call to the host with ports 587, 465 and 25.

License

See the LICENSE file.