No mail date and now no mail

Quit Mail.

In your Home folder. open Library folder, open Mail folder in that, look for the Envelope Index, and drag it to the Desktop.

Then in your Home folder. open Library folder, open Caches folder in that, look for the Mail, and drag it to the Desktop.Move Envelope Index to the Desktop in...

/Users/YourUserName/Library/Mail/Envelope Index

Move this folder to the Desktop...

/Users/YourUserName/Library/Caches/Mail

Custom installs in Mac OS X 10.4

http://docs.info.apple.com/article.html?artnum=301229

Here's a complete list of all the custom installation options available with Optional Installs.mpkg:

* Applications
o Address Book 4.0
o iCal 2.0
o iChat 3.0
o iTunes 4.7.1
o Mail 2.0
o Oxford Dictionaries
o Safari 2.0
o X11

Is it possible to find the mac mail app somewhere to reinstall.

Yes, that's why I included this & everything after it in my above post...

Custom installs in Mac OS X 10.4

But if those files/folders don't exist, I think you have bigger problems looming, I'd do this first...

"Try Disk Utility

1. Insert the Mac OS X Install disc that came with your computer, then restart the computer while holding the C key.
2. When your computer finishes starting up from the disc, choose Disk Utility from the Installer menu. (In Mac OS X 10.4 or later, you must select your language first.)
Important: Do not click Continue in the first screen of the Installer. If you do, you must restart from the disc again to access Disk Utility.
3. Click the First Aid tab.
4. Click the disclosure triangle to the left of the hard drive icon to display the names of your hard disk volumes and partitions.
5. Select your Mac OS X volume.
6. Click Repair. Disk Utility checks and repairs the disk."

http://docs.info.apple.com/article.html?artnum=106214

Then Safe Boot from the HD, (holding Shift key down at bootup), run Disk Utility in Applications>Utilities, then highlight your drive, click on Repair Permissions, reboot when it finishes.