Sneak peek at a new feature coming soon to iOS and OS X. If you store lots of email addresses in a map then there is a single(ish) click way of turning them into a list of recipients.
Right click on a branch then choose 'Copy as' - 'Email Addresses'. This will place all the email addresses in that branch onto the clipboard (including email addresses in notes etc.)
Once on the clipboard you can Paste the addresses into a new email...
Same is true on the iOS version - and that will also offer to create the email for you.
Great for managing contact lists in a more visual way.