connectbutton.html

<a href="https://outlook.office.com/connectors/ConnectToO365?state=myAppsState&app_name=My Custom App&app_logo_url=http://www.catb.org/hacker-emblem/glider.png&callback_url=https://vrdmn.local.net:44301/Start">
    <img src="https://connecttoo365.blob.core.windows.net/images/ConnectToO365Button.png" alt="Connect to Office 365"></img>
</a>