Outlook 2007 Cannot Send

I have a user getting sporadic errors in Outlook 2007. I have Exchange 2010.
It has happened to internal and external recipients.
If I delete the text from all previous emails in my reply, then it will send just fine.
This user has no issues in termserv or in OWA.
I have put them in cached and non-cached mode and have recreated their OST.

The error that pops up is "cannot send"
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Have you tried to re-create their outlook profile?  uninstalling and then reinstalling outlook?  Can you get them to log into another computer to check their outlook?
Outlook creates an offline OST file - this sometimes gets corrupted..
Disable offline cach from the Mail profile and delete the ost file.
Try using Outlook without offline cache.
You can select offline cache again at a later date.
The answer above has the same effect as recreating the OST file.
rtlawAuthor Commented:
I have recreated her profile and it works fine from other computers.
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Can anyone log into the comptuer thats having trouble to check email?  If not then I would speculate the software needs re-installed
try run the following command from the shell

Add-MailboxPermission -Identity "MAILBOX HERE" -User "USERNAMEHERE" -AccessRights FullAccess
rtlawAuthor Commented:
Last thing I did was remove the NK2 file and make that cache rebuild.
Closing this with no result, as the issue keeps recurring.

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rtlawAuthor Commented:
no solution given.
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