Messages "try again" send error

Sign out of iMessage and sign back in. If you still have problems, take the steps suggested in the support article linked below:

FaceTime, Game Center, Messages: Troubleshooting sign in issues

There was a not activated email adress for my apple id but i deleted that (because i coulnd get a activate email).

Sorry, I don't understand this.

Please read this whole message before doing anything.

Back up all data.

Quit Messages if it’s running.

Step 1

Hold down the option key and select

Go ▹ Library

from the Finder menu bar. Move the following items from the Library folder to the Trash (either may not exist):

• Caches/com.apple.Messages
• Caches/com.apple.imfoundation.IMRemoteURLConnectionAgent

Leave the Library folder open. Log out and log back in. Try Messages again. If it works now, stop here. Close the Library folder.

Step 2

If you still have problems, quit Messages again. Go back to the Finder and move the following item from the open Library folder to the Desktop:

Messages

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

Test. If Messages now works, delete the Messages folder on the Desktop. Otherwise, quit Messages again. Put back the folder you moved, overwriting the newer one that may have been created in its place, and continue.

Step 3

In the Preferences subfolder, there may be several files having names that begin with any of the following strings:

• com.apple.iChat
• com.apple.imdsmsrecordstore
• com.apple.imessage
• com.apple.imservice

Move them all to the Desktop. There may also be a file with the name "com.apple.imagent.plist". Move that to the Trash.

Also in the Preferences folder, there's a subfolder named "ByHost". Open it and do the same thing.

Log out and log back in. Test again. This time Messages should perform normally, but your settings will be lost. You may be able to put back some of the files you moved to the Desktop in this step. Relaunch and test after each one. Eventually you should find one or more that causes Messages to malfunction. Delete those files and recreate whatever settings they contained.

If the issue is still not resolved, quit Messages again and put all the items you moved to the Desktop back where they were. You don’t need to replace the items you moved to the Trash. Stop here and post again.

If you later decide that you don’t like the results of steps 2 and 3, you can undo them completely by quitting Messages and restoring the items you deleted in those steps from your backup.

I thought this helped but it did not

Why did you think that, and what made you change your mind? Are you only unable to send to one recipient, or to all?

What kind of messaging account are you using -- iMessage or something else? When you can't send messages, are your other Internet applications working, such as Safari and Mail?

Does iMessage work on your phone?

Please read this whole message before doing anything.

This procedure is a test, not a solution. Don’t be disappointed when you find that nothing has changed after you complete it.

Step 1

The purpose of this step 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 guest users” (without the quotes) in the search box. Don't use the Safari-only “Guest User” login created by “Find My Mac.”

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.

Test while logged in as Guest. Same problem?

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.

*Note: If you’ve activated “Find My Mac” or FileVault, then you can’t enable the Guest account. The “Guest User” login created by “Find My Mac” is not the same. Create a new account in which to test, and delete it, including its home folder, after testing.

Step 2

The purpose of this step is to determine whether the problem is caused by third-party system modifications that load automatically at startup or login, or by a peripheral device.

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:

• Shut down your computer, wait 30 seconds, and then hold down the shift key while pressing the power button.
• When you see the gray Apple logo, release the shift key.
• If you are prompted to log in, type your password, and then hold down the shift key again as you click Log in.

Safe mode is much slower to boot and run than normal, and some things won’t work at all, including wireless networking on certain Macs. The next normal boot may also be somewhat slow.

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.

*Note: If FileVault is enabled, or if a firmware password is set, or if the boot volume is a software RAID, you can’t boot in safe mode.

Test while in safe mode. Same problem?

After testing, reboot as usual (i.e., not in safe mode) and verify that you still have the problem. Post the results of steps 1 and 2.

Also make sure you check this site before doing anything:

http://www.apple.com/support/systemstatus/

As an example, as I write this, Apple is having iMessage issues which result n many of the same symptoms referred to in this thread, though only over the past few hours.

That doesn't explain why his phone is working.