HELP. I cant send email invites

Hi, my name is Jim. I am a workplace BASIC Free user.  I have used zoom before (w/ windows7) and it automatically allowed me to use my desktop comcast email to invite guests. I recently upgraded to windows10 and now when I click default mail ... it forces me to use and join outlook mail and use the cloud. I do not have an outlook mail account (I do not want a outlook account or my info going to a cloud) how can I get the email default button to send me to my comcast email address so that I can invite guests?  I am stuck and I am unable to invite guests.