Easier way to make sure all contacts included in email

I’m looking for a simpler way to make sure that all contacts are included on emails sent from GS.  I have template emails saved into Success Plans which allows me to send emails from the CTA/Tasks.  Currently, I have to open a separate tab to reference the contacts to make sure they all get added to the emails -  primary in the To: line and then all other parties in the cc: line.  It’s very manual and takes forever.  Is there a way to create a company group which would allow me to email everyone in the group at once and ensure no one gets left off.  I’ve looked through Ideas and I don’t see anything that requests a dropdown off all contacts associated with the company, a way to create group email or another way around this.  It’s very frustrating.