It would be beneficial to have the ability to select Contacts from a View with the check-boxes provided, and begin an email right from the Contacts page.
Currently, the only way to email a group of Contacts across multiple Companies is to begin emailing one of them from the Contact record, and manually add the rest.
This functionality is needed for any conversation involving two-way engagement (just like a cc list on an email), in which the contacts have personal relationships with each other and want to collaborate. This is totally separate from existing functionality which "markets to" lists of people using Marketing emails or Sequences.