FO-6 Validate an email address

Write a single regular expression that validates an email address from the user. The rules are: The first part until the @ sign can contain any character, letter, digit. Special characters like the ., the $ or the  # are also accepted but only those. This part should contain at least 2 and max 50 characters.

Then follows the literal @, after this, we accept a minimum of 4 and maximum of 50 letter characters. 

Then follows the literal . 

Then for now we accept only addresses that match either com, net or org.

For example the email address:

kostas.diakogianni$23@gmail.com is accepted and valid. But not the:

kostas.diakogi@nnis23@gmail.com is not!