Open Message index with Thunderbird in OmniOutliner Link

Using OmniOutliner 5.4.2 with mac mail. I can drag and drop message indexes on to my outliner document which displays the message subject title with a linkable link. When clicked it opens mail and that specific email.

Now if I do the same in thunderbird. It does put the link there


However, when click on the link it doesn’t seem to open the thunderbird client.

Instead you have the following message from macOS
There is no application set to open the URL mailbox:///Users//Library/Thunderbird/Profiles/8e1sp0lr.default/Mail//Inbox?number=73217.

When click on the choose app thunderbird is greyed out. This might not be an omni outliner question exclusively but i thought maybe someone else is doing this and found a work around.

Has anyone found a work around?