While creating an appointment ,i am getting this error .
"At least one recipient does not have an e-mail address or is marked as "Do Not Allow" e-mail."
Can anyone give a solution for this.
Check the User, Account or Contact records and ensure Allow E-mail and Allow Bulk E-mail are set to yes. It is odd that you are trying to create an appointment and there is a check for e-mail but try that and lets see what happens.