One or more parameter values are not valid (Outlook error) Solved!

Recently, I came by an error message I hadn’t seen before in Outlook 2007 & 2010. Upon hitting the “send” button, immediately the computer would pop up an error message, which reads: “Could not complete the operation, one or more parameter values are not valid.” You didn’t even have time to see if the message sent – it wouldn’t send at all. It turns out, what had happened, was that the address in Outlook’s address had book had somehow become corrupted. I won’t pretend to know what caused the problem, but I will provide you with a quick and easy solution.

  1. Start a new email message.
  2. Begin typing the address of the person you’re sending to.
  3. When it appears in the drop down, highlight it using the arrow keys on your keyboard.
  4. So you don’t forget it, I advise WRITING DOWN the email address now.
  5. Press the DEL (DELETE) key on your keyboard.
  6. Now RE-TYPE (do not copy and paste) the email address you are sending to.
  7. Enter a message and send it!

You shouldn’t have ANY problems when you click the send button after that!