Error on sending mail

[shannu420]

Sender InvalidClientTokenId The security token included in the request is invalid 3c9c1cfa-65b4-11e4-86be-93a1f715622b

The above error occurs when email is send.

[shannu420]

help me to fix this above error dudes

[shankarnewton]

i'm too getting the same error! any chance if you/someone got a solution to fix this out?