Run gofmt.
Replace errors.New(fmt.Sprintf(...)) with fmt.Errorf(...)
Use consistent receiver names.
Remove inferrable type declarations.
Remove else after block with return statement.
Use descriptive receiver names.
Use form errFoo for error variables.
Change Id to ID.
Change private Xml variables to XML.
Lowercase error strings.
Remove punctuation from end of error messages.
Replace Smtp with SMTP.
Use var to define empty arrays.
Merge pull request #58 from benmanns/golint

Golint
Fixed header.
Minor changes.
Fixed minor format bug. #61.