How to push a selected email to a service provider in Catalina Beta?

Our app uses a service provider to get a seleted email in default Mail.app. This works perfect in High Sierra but not with Catalina any more. The pasteboard in Catalina is empty. Here is a code snipped of our plist file, that defines the service provider:

<dict>

<key>NSKeyEquivalent</key>

<dict>

...

</dict>

<key>NSMenuItem</key>

<dict>

...

</dict>

<key>NSMessage</key>

<string>...</string>

<key>NSPortName</key>

<string>...</string>

<key>NSRequiredContext</key>

<dict>

<key>New item</key>

<string></string>

</dict>

<key>NSSendTypes</key>

<array>

<string>public.plain-text</string>

<string>public.rtf</string>

<string>public.contact</string>

<string>NSURLPboardType</string>

<string>NSFilenamesPboardType</string>

<string>NSFilesPromisePboardType</string>

<string>NSPasteboardTypeURL</string>

<string>NSPasteboardTypeFileURL</string>

<string>NSRTFDPboardType</string>

<string>NSPasteboardTypeMultipleTextSelection</string>

<string>NSPasteboardTypePDF</string>

</array>

</dict>

Maybe we have to add another pasteboard type? Or is this behaviour another bug or even feature of Catalina? Has someone an idea?