You have some proposals that you would like not to acknowledge and FreeBusy Scheduling assistant sends you a mail to "Accept & Add to Calendar"; you would rather decline this meeting proposal and possibly inform the proposer why this meeting to decline.
Freebusy offers a means for you to do this right within the product. Here is how it works:
When you get a proposal for a new meeting and a mail is received from your end, It is automatically registered in your Agenda.
Next, you find the date which the proposed meeting was scheduled for, you find this information through your mail and you locate it in your agenda.
When you do find the date, you can go ahead and accept or decline the proposal.
Note, that the blue circles indicate that these dates, have activities in them and you can manage them from Agenda in FreeBusy.
When you decline a meeting, you can include a reason which would be sent to the proposer.
This is how you decline meeting from Freebusy.