Use Mail app for mailto links but not receive? I use the Outlook email app but because Apple doesn't allow changing associated apps for things like mailto links, whenever I click on "Send feedback" in an app or an email address on a website, I'm presented with "Please configure an email account". 

Is there any way to configure the Mail app for send only? I don't want to have two copies of my inbox. (This is for a GMail account)

CLARIFICATION - This is on an iPhone not a Mac
Use RCDefaultApp to configure your default Mailer.
It installs as a Control Panel.