Please I need to extend the number of mails per campaigns as am trying to send sort of campaigns with large number of mails and Gizmo gives me an error. is it applicable or not? and if not what is the maximum number of mails which i can send per campaigns.
This will depend on the Plan Level of your SurveyGizmo account (Pro, Enterprise, etc.). This article will help shed some light on the limits for each plan level and will also cover how you can purchase credits to increase your limits:
Hope this helps!