MailFormatter should handle string of multiple addresses.

Problem/Motivation

I am migrating some of our site's emails from using Business Rules to using Message. Our mail system has defaults for Business Rules, Commerce and other modules which generate emails (sadly Drupal still has no common mechanism for sending emails). Our default Formatter is Mimemail which gets used by Message module as it doesnt provide its own formatter.

I was surprised to see that our To address, passed in the form of "Name 1 , Name 2 " was having the 2nd address clipped. Tracking this down i see the mimeMailAddress helper method has a few different options for passing in email addresses, but not this one. Even though most other mail formatter modules work with this.

Odd as well that it silently clips this with no warnings or errors.

Would be nice if this was an allowed email format.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes