What happens if you hover your mouse over the senders name? On my system the address pops up. This would be in the header of the Message Pane. This should only be the case for contacts that are in one of your address books which usually indicates a legitimate sender. You will notice a color filled star after any contact that exists in one of your address books.

If that does not work for you go to the menu bar and select Tools-Options-Advanced-Reading & Display

Uncheck the last option for displaying only the name for contacts in your address book.

No menu bar? Press the alt key.

I'm asking here because I'm using Thunderbird on the computer for my email. When I hold my mouse over the name nothing is displayed.

I have gone to Tools-Options-Advanced-Reading & Display to uncheck the last option for displaying only the name for contacts in your address book.

It has not made any difference.

What I described only happens in the Message Pane display after you select the message header. I added this comment to my original post later. Press F8 to turn the message pane on if not already active.

If I have the message pane switched on is it not the same as opening the message?

I'm trying to find out who is sending the email before I open it. With my Yahoo mail I only have to hold my mouse over the senders name for it to show. I can therefore delete a SPAM email before opening it.

You can have a column added to the Threads Pane (message list) that displays the senders' addresses: Show Address Only (How to install). Tested and working in TB 31 & 38.

sfhowes said

You can have a column added to the Threads Pane (message list) that displays the senders' addresses: Show Address Only (How to install). Tested and working in TB 31 & 38.

Thanks for that Add-On.

Problem solved :)