Make the API more flexible and document parameters.

[avdb13]

Trying to move away from lettre in favor of an actively maintained crate. I immediately noticed that there's no documentation for the API and there's a lot of implementations missing that one would expect to be present such as impl From<EmailAddress> for Address.
Great job so far though, wish I had the time to offer a helping hand.

[mdecimus]

Hi,

I agree but at the moment I do not have time to work on extending the documentation. I'll leave this open in case someone wants to contribute to the documentation.

[avdb13]

Hi,

I agree but at the moment I do not have time to work on extending the documentation. I'll leave this open in case someone wants to contribute to the documentation.

Sad to hear, I mean I just need it for email verification so it's not really worth it right now.