[MlMt] "Software Update Disabled"

[Thomas Baker]

I am trying to set up MailMate on macOS Catalina 10.15.3.
When I open MailMate, I get a message:

    Software Update Disabled
    
    MailMate is running on a read-only file system and 
    can therefore not be updated.

    If you downloaded MailMate from the internet then 
    moving it out of the Downloads folder should solve 
    the problem.

I installed from MailMateBeta.tbz into the /Applications 
folder.  The permissions of that folder were initially:

    drwxr-xr-x 3 root wheel 96 Oct 24 15:33 MailMate.app/

I changed the permissions to my personal account:

    drwxr-xr-x 3 tbaker staff 96 Oct 24 15:33 MailMate.app/

But I still get the message.  

I suppose I could just check the box for "Do not show
this message again", but I'd like to understand what
folder MailMate thinks is read-only (and whether this 
could cause trouble in other ways).

Many thanks,
Tom