Added - Pull 348: Allows users to submit rfc822 formatted email addresses - Big thanks to [Matt Bernier](https://github.com/mbernier) for the pull request!
5.2.1
Fixed - Pull 364: Install prism with non superuser account - Big thanks to [meahow](https://github.com/meahow) for the pull request!
5.2.0
Added - Pull 335: Permit unicode string values with Substitution helper - Big thanks to [Mehron Kugler](https://github.com/mehronkugler) for the pull request!
5.1.0
Added - Pull 338: Allow the `__str__` method for the `Mail` object return an `String` instead of a `NoneType` - Solves 292: The `__str__` method of the `Mail` class, doesn't actually return anything - Big thanks to [belfazt](https://github.com/belfazt) for the pull request!
5.0.1
Fixed - Pull 337, fixes issue 366 - On install, some experienced: `ValueError: ("Expected ',' or end-of-list in", 'python-http-client ==3.0.*', 'at', '*')`
5.0.0
BREAKING CHANGE - The breaking change actually happened in [version 4.2.1](https://github.com/sendgrid/sendgrid-python/releases/tag/v4.2.1), where I mistakenly applied a patch version bump. See issues #328 and 321 for details. - This version (5.0.0) replaces error handling via HTTPError from urllib in favor of custom error handling via the [HTTPError class](https://github.com/sendgrid/python-http-client/blob/HEAD/python_http_client/exceptions.py) as was the case in version 4.2.0.