Are you using any password characters other than numbers and letters? Some older systems may not accept non-alphnumeric characters like !#$%&?+. If so, reset your email password using just alpha-numerics and you should be good to go. Another issue could be password length if it's more than 8 characters so shortening to a password with no more than 8 alpha-numerics might be the solution.
If you aren't comfortable changing the password on your email account you can get a free email account from google, yahoo, mail.com and many others and just use that for your camera and other low security applications. I do that myself.