Change README to reflect more extensible usage
Merge pull request #30 from nateberkopec/master

Suggestions for README examples
Update README.md

added gem with version from rubygems
Fix a Rails 2 compatibility issue.
Show SMTP envelope if available. See mikel/mail#477.
Merge pull request #32 from joshnabbott/master

Fix a Rails 2 compatibility bug with multipart emails
Merge pull request #31 from svenhedin/patch-1

Updated README.md
Include SMTP envelope address in the main header list
Breathing room for the mail headers
Only show SMTP envelope if it differs from the message headers