Perhaps you mean you can see all the headers and only need to see info such as From, TO, Subject, Date. If this is the case then it sounds like you are currently viewing All the headers, so try changing the following setting: If you use the top 'Menu Bar' which has 'File', 'Edit', 'View' etc then 'View' > 'Headers' > select 'Normal'

Otherwise: Menu app icon (icon with 3 horizontal line) > 'View' > 'Headers' > select 'Normal'

Many thanks. I think I showed up my ignorance of Thunderbird!!