Email Validator

A simple program which checks for Email Address Validity in three simple checks

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How it works

• Syntax check, Checks for basic email address syntax using Regex

• DNS check, Checks for domain validity and retrieving record names

• SMTP check, HELO, MAIL FROM and RCPT TO commands are implemented. In the RCPT, If the server sends back a 250, then that means we are good to send an email (the email address exists), otherwise the server will return a different status code (usually a 550), meaning the email address does not exist on that server.

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Requirements (Py modules used)

• re (Regex)
• dns
• smtplib
• socket

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TESTCASES

#INPUT
mdsaaalikgmalia.com
#OUTPUT
Check 1 FAILED! Bad Syntax, Invalid Email!

#INPUT
mdsaaalik@gmalia.com
#OUTPUT
Check 1 (Syntax) Passed
Check 2 FAILED! The domain gmalia.com does not exist, Invalid Email!

#INPUT
salik_invalid@gmail.com
#OUTPUT
Check 1 (Syntax) Passed
Check 2 (DNS - gmail-smtp-in.l.google.com.) Passed
Check 3 FAILED! The user salik_invalid does not exist, Invalid Email!

#INPUT
mdsaaalik@gmail.com
#OUTPUT
Check 1 (Syntax) Passed
Check 2 (DNS - alt4.gmail-smtp-in.l.google.com.) Passed
Check 3 (SMTP response) Passed
mdsaaalik@gmail.com is a VALID email address!

#INPUT
mdsaaalik@yahoo.com
#OUTPUT
Check 1 (Syntax) Passed
Check 2 (DNS - mta5.am0.yahoodns.net.) Passed
Check 3 HALTED! The domain yahoo.com , either does not have an SMTP or have restricted access through external scripts

By Md Salik