Parameter Description: EmailSubject sets the value of the Subject field.
This is a Conga Quote Generation button parameter and is not to be confused with the Subject line in the actual Conga Quote Generation Email Template. If you set this parameter and use EmailTemplateId, the value you enter here replaces the subject of the email template. Use + to indicate spaces. You can also use dynamic field content for the parameter value: &EmailSubject=Account+Brief+for+{!Account.Name}