email accounts won't delete from mail app on Droid Razr (ICS)

[Didier9]

How can I delete email accounts from the stock email app on my Droid Razr (ICS)?
I have given up on the stock Android mail client. It did not work under Gingerbread and still does not work under ICS. Even the gmail accounts did not work, which is interesting. I now use K9, which seems to be working (I have two gmail accounts, a yahoo mail account, a hotmail account and two pop mail accounts)
I just want to stop the stock mail client from trying to download messages and there are 3 mail accounts that I cannot remove (gmail, yahoo and Cox pop mail).
I get a message saying "invalid credentials" when I try to remove the accounts (which never worked in the first place because I was already getting the invalid credential message when trying to set them up).
Why would I need credentials to remove an account from the phone is beyond me.
But I don't need to understand why Google is unable to make a mail client work with their own mail system, I just want to delete the accounts.
Any help appreciated.
Thanks in advance,
Didier

PS: I also use an iPhone 4S that my company gave me for an overseas trip, and all email accounts worked the first time on that phone, and they work over the air or over WiFi just the same, in all locations in the 3 countries where I just travelled. I consider the state of email on Android to be a disgrace with an otherwise remarkable operating system.