If you setup an email server on your PC, you can easily send unlimited emails with a custom “From” address 
This is particularly helpful if you want to send emails programmatically for some reasons (I like to send unimportant emails and small attachments via Python).
To setup a mail server on Ubuntu, just install the “postfix” package:
sudo apt-get install postfix
Now you can send emails with php, python or even by typing codes on the terminal.
It was simple. Wasn’t it?