Log into your Confluence instance as an administrator.
Click the admin dropdown and choose Atlassian Marketplace. The "Find new add-ons" screen loads.
Locate E-Mail this Page via search. The appropriate add-on version appears in the search results.
Click "Try free" to begin a new trial or Buy now to purchase a license for the E-Mail this Page app. You'll be prompted to log into MyAtlassian if you're logged out. The E-Mail this Page app begins to download.
Enter your information and click "Generate license" when redirected to MyAtlassian.
Click Apply license. If you're using an older version of UPM, you can copy and paste the license into your Confluence instance.
Configure custom CSS for the e-mails
Go to the Universal Plugin Manager and choose E-Mail this Page.
Click the Configure-Button.
Use the magnifier symbol to select the confluence groups who are allowed to send mails (Alternative: you can enter the names and split them with a comma).