manifest.xml

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<OfficeApp xmlns="http://schemas.microsoft.com/office/appforoffice/1.1"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:bt="http://schemas.microsoft.com/office/officeappbasictypes/1.0"
  xmlns:mailappor="http://schemas.microsoft.com/office/mailappversionoverrides/1.0"
  xsi:type="MailApp">
  <Id>e2d5a8db-8521-4f18-b851-dfacb0c7222b</Id>
  <Version>1.0.0.0</Version>
  <ProviderName>Contoso</ProviderName>
  <DefaultLocale>en-US</DefaultLocale>
  <DisplayName DefaultValue="Git the gist" />
  <Description DefaultValue="Allows users to access their GitHub gists." />
  <IconUrl DefaultValue="https://localhost:3000/assets/icon-64.png" />
  <HighResolutionIconUrl DefaultValue="https://localhost:3000/assets/icon-128.png" />
  <SupportUrl DefaultValue="https://www.contoso.com/help" />
  <AppDomains>
    <AppDomain>https://www.contoso.com</AppDomain>
  </AppDomains>
  <Hosts>
    <Host Name="Mailbox" />
  </Hosts>
  <Requirements>
    <Sets>
      <Set Name="Mailbox" MinVersion="1.1" />
    </Sets>
  </Requirements>
  <FormSettings>
    <Form xsi:type="ItemRead">
      <DesktopSettings>
        <SourceLocation DefaultValue="https://localhost:3000/taskpane.html" />
        <RequestedHeight>250</RequestedHeight>
      </DesktopSettings>
    </Form>
  </FormSettings>
  <Permissions>ReadWriteItem</Permissions>
  <Rule xsi:type="RuleCollection" Mode="Or">
    <Rule xsi:type="ItemIs" ItemType="Message" FormType="Read" />
  </Rule>
  <DisableEntityHighlighting>false</DisableEntityHighlighting>
  <VersionOverrides xmlns="http://schemas.microsoft.com/office/mailappversionoverrides"
    xsi:type="VersionOverridesV1_0">
    <Requirements>
      <bt:Sets DefaultMinVersion="1.3">
        <bt:Set Name="Mailbox" />
      </bt:Sets>
    </Requirements>
    <Hosts>
      <Host xsi:type="MailHost">
        <DesktopFormFactor>
          <FunctionFile resid="Commands.Url" />
          <!-- Message Compose -->
          <ExtensionPoint xsi:type="MessageComposeCommandSurface">
            <OfficeTab id="TabDefault">
              <Group id="msgComposeCmdGroup">
                <Label resid="GroupLabel" />
                <Control xsi:type="Button" id="msgComposeInsertGist">
                  <Label resid="TaskpaneButton.Label" />
                  <Supertip>
                    <Title resid="TaskpaneButton.Title" />
                    <Description resid="TaskpaneButton.Tooltip" />
                  </Supertip>
                  <Icon>
                    <bt:Image size="16" resid="Icon.16x16" />
                    <bt:Image size="32" resid="Icon.32x32" />
                    <bt:Image size="80" resid="Icon.80x80" />
                  </Icon>
                  <Action xsi:type="ShowTaskpane">
                    <SourceLocation resid="Taskpane.Url" />
                  </Action>
                </Control>
                <Control xsi:type="Button" id="msgComposeInsertDefaultGist">
                  <Label resid="FunctionButton.Label" />
                  <Supertip>
                    <Title resid="FunctionButton.Title" />
                    <Description resid="FunctionButton.Tooltip" />
                  </Supertip>
                  <Icon>
                    <bt:Image size="16" resid="Icon.16x16" />
                    <bt:Image size="32" resid="Icon.32x32" />
                    <bt:Image size="80" resid="Icon.80x80" />
                  </Icon>
                  <Action xsi:type="ExecuteFunction">
                    <FunctionName>insertDefaultGist</FunctionName>
                  </Action>
                </Control>
              </Group>
            </OfficeTab>
          </ExtensionPoint>
        </DesktopFormFactor>
      </Host>
    </Hosts>
    <Resources>
      <bt:Images>
        <bt:Image id="Icon.16x16" DefaultValue="https://localhost:3000/assets/icon-16.png" />
        <bt:Image id="Icon.32x32" DefaultValue="https://localhost:3000/assets/icon-32.png" />
        <bt:Image id="Icon.80x80" DefaultValue="https://localhost:3000/assets/icon-80.png" />
      </bt:Images>
      <bt:Urls>
        <bt:Url id="Commands.Url" DefaultValue="https://localhost:3000/commands.html" />
        <bt:Url id="Taskpane.Url" DefaultValue="https://localhost:3000/taskpane.html" />
      </bt:Urls>
      <bt:ShortStrings>
        <bt:String id="GroupLabel" DefaultValue="Git the gist" />
        <bt:String id="TaskpaneButton.Label" DefaultValue="Insert gist" />
        <bt:String id="TaskpaneButton.Title" DefaultValue="Insert gist" />
        <bt:String id="FunctionButton.Label" DefaultValue="Insert default gist" />
        <bt:String id="FunctionButton.Title" DefaultValue="Insert default gist" />
      </bt:ShortStrings>
      <bt:LongStrings>
        <bt:String id="TaskpaneButton.Tooltip"
          DefaultValue="Displays a list of your gists and allows you to insert their contents into the current message." />
        <bt:String id="FunctionButton.Tooltip"
          DefaultValue="Inserts the content of the gist you mark as default into the current message." />
      </bt:LongStrings>
    </Resources>
  </VersionOverrides>
</OfficeApp>