Opening template acts different in different accounts

Hi All, I have three different email accounts. In my main gmail account, if I double-click on a template, it opens up in a new email with the content of the template already in there (which is how I want it to behave.) In my other two accounts, double-clicking a template just opens a new tab with the contents of the template displayed, as it would if I double-clicked any email in my inbox. I've been through the settings, comparing them for all three accounts, and I can find no difference anywhere. Right-clicking on the Template folder offers no obvious path to follow, nor does right-clicking on the template itself. Any ideas why the difference in behavior, and/or suggestions on how to change the not-gmail account so it behaves the same way as the gmail account (double-click opens new pre-filled email) ?? Thanks!!!