Client Outlook and OWA issue on MAC

Please I need urgent assistance on this:

How can I stop meeting invite receipt responses on my MAC outlook since the option windows had (Automatically process meeting requests and responses to meeting requests and polls) is not available on MAC. 

I have series of meeting invites on my outlook calendar and which I have accepted them once. But outlook keeps sending invite acceptance response to the meeting author repeatedly and automatically every 10mins - 15mins. 

Please what may be the cause and remedy to stop this frustration.

I need help.