Mail problems-can't click reply and more

Question

When I first got my Imac I transfer all data from my older machine running OS X. Mail worked just fine for a couple of weeks then it started having the same problem I have now. I tried rebuilding and throwing away the preference but no luck so I gave up and reinstalled Mail which caused me to lose my emails and accounts. I set up everything again and things ran fine for the past year. Now I’m having the same problem.
My emails accounts are POP. I have no problem receiving them or reading them. When you click the “reply” or “reply all” buttons you get no response. You can click “forward” and type in a email address but then no further action can be taken. When you click “new message” it will only let you type 2 characters in the message and then beeps at you. I made no changes to the system before this happen. Everything was working fine one day and the next day the problems arrived. Any suggestions?
Imac 2ghz PowerPC G5   Mac OS X (10.4.9)  

Answer 1

What you say about reinstalling Mail, besides being a bad idea, doesn’t make sense to me. Reinstalling Mail cannot have caused you to lose anything — actually, that’s precisely why reinstalling Mail is rarely appropriate or useful to solve a problem.
If you lost your mail it has to be because you did something else you shouldn’t have done either, such as deleting the accounts or something like that. Or maybe nothing has really been deleted and your old mail is just inaccessible as a result of something you did...
Anyway, the problem you describe is caused by some Launch Services cache or preferences corruption that affects the built-in spell checker. The following article describes how to manually reset Launch Services — the notes at the bottom of the article also provide information about the side effects of deleting each of the files involved:
Resetting Launch Services
If you prefer using a cache cleaning utility instead of following the manual procedure described in the previous article, take a look at this other article for general troubleshooting and cache-cleaning procedures. Actually, you should also verify/repair the startup disk (not just permissions), as described there:
Resolving Disk, Permission, and Cache Corruption
The most appropriate utility for this particular problem probably is Tiger Cache Cleaner, but you may also want to consider other utilities, such as OnyX, or Cache Out X, which are free. Whatever utility you choose, be sure to read this first:
Side effects of System cache cleaning
As an example, this is how you should proceed with OnyX:
1. Quit all applications.
2. Launch OnyX and enter your administrator password.
3. Go to Maintenance > Reset and check LaunchServices database.
4. Un-check any other pre-checked options.
5. Click the Execute button.
6. Restart the computer.
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BTW, after having verified/repaired the startup disk (as described above), if the version of the system software on the Install disc used to reinstall Mail is earlier than what you’re using now (and only in that case), then you must also reinstall the Combo Update for the type of computer and the version of Mac OS X you’re using, to bring Mail back in sync with the rest of the system:
About the Mac OS X 10.4.9 Combo Update
Mac OS X 10.4.9 Combo Update for PowerPC
Mac OS X 10.4.9 Combo Update for Intel
After installing the Combo Update, the computer may restart twice and the first restart may take several minutes. This is normal.
You may want to take a look at the following articles for guidelines on how to properly install system updates:
Troubleshooting installation and software updates
Installing software updates
Basically, you should verify/repair the startup disk before installing the update, no applications should be running while installing it, and you may experience unexpected results if you have third-party system software modifications (not normal applications) installed.