can't compose, reply or forward mail in 10.7.3

Please read this whole message before doing anything.

This procedure is a diagnostic test. It won’t solve your problem. Don’t be disappointed when you find that nothing has changed after you complete it.

The purpose of this exercise is to determine whether the problem is localized to your user account. Enable guest logins and log in as Guest. For instructions, launch the System Preferences application, select “Help” from the menu bar, and enter “Set up a guest account” (without the quotes) in the search box.

While logged in as Guest, you won’t have access to any of your personal files or settings. Applications will behave as if you were running them for the first time. Don’t be alarmed by this; it’s normal. If you need any passwords or other personal data in order to complete the test, memorize, print, or write them down before you begin.

As Guest, launch the application(s) and test. Same problem(s)?

After testing, log out of the guest account and, in your own account, disable it if you wish. Any files you created in the guest account will be deleted automatically when you log out of it.

Please read this whole message before doing anything.

This procedure is a diagnostic test. It’s unlikely to solve your problem. Don’t be disappointed when you find that nothing has changed after you complete it.

The purpose of this exercise is to determine whether the problem is caused by third-party system modifications that load automatically at startup or login. Disconnect all wired peripherals except those needed for the test, and remove all aftermarket expansion cards. Boot in safe mode and log in to the account with the problem. The instructions provided by Apple are as follows:

• Be sure your Mac is shut down.
• Press the power button.
• Immediately after you hear the startup tone, hold the Shift key. The Shift key should be held as soon as possible after the startup tone, but not before the tone.
• Release the Shift key when you see the gray Apple icon and the progress indicator (looks like a spinning gear).

Safe mode is much slower to boot and run than normal, and some things won’t work at all, including wireless networking on some Macs.

The login screen appears even if you usually log in automatically. You must know your login password in order to log in. If you’ve forgotten the password, you will need to reset it before you begin.

Test while in safe mode. Same problem(s)?

After testing, reboot as usual (i.e., not in safe mode.)

Back up all data if you haven’t already done so. Before proceeding, you must be sure you can restore your system to the state it’s in now. If you skip this step, no one but you will be responsible for the consequences.

Select all your mailboxes, and then select Mailbox ▹ Export Mailbox from the Mail menu bar. Export the mailboxes to the Desktop folder.

Make a note of the settings for all your Mail accounts -- everything you'd need to reconstruct the settings from scratch. Quit Mail.

In the Finder, hold down the option key and select Go ▹ Library from the menu bar. Move the following items from the folder that opens to the Trash (some may not exist):

Caches/com.apple.mail

Saved Application State/com.apple.mail.savedState

Leave the Finder window open for now.

Relaunch Mail. If the problem is solved, you’re done. Delete the exported mailboxes. Otherwise, quit Mail and move these items from the open Library folder to the Desktop:

Mail

Preferences/com.apple.mail.plist

Preferences/com.apple.mail.searchhistory.plist

(Note: you are not moving the Mail application. You’re moving a folder named “Mail.”)

Relaunch Mail. It will behave as if you were setting it up for the first time. Go through the setup process with one of your accounts, using the information you noted earlier. Test. Same problem?

If there’s no improvement, quit Mail again and put back the items you moved to the Desktop, replacing any newer ones that may have been created in their place. You don’t need to replace the items you moved to the Trash.

If the issue is resolved, recreate the rest of your Mail settings, then import your mailboxes, delete the items on the Desktop, and close the Finder window.

I had this SAME problem, I could not forward, reply or compose jack and went thru all this rigamaroll with plists and prefrences and you name its....what "fixed" the problems was I took my mail out of "full screen" and BAM it worked like it was never messed up...