I am currently in the middle of doing scientific research and sending out surveys to about 200 participants.My Zoho Account is linked to my gmail account ( info@xpatsinkorea.com). Yesterday, I tried sending all of them an email with a linkbut got the following message: 

Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the relay  smtp.zoho.com  [165.254.168.48]

550 5.4.6Mail rate exceeded limit

Today, I tried sending more emails but got the same problem after sending around 60 emails. 

Is there any way to fix this problem? Like unblocking my email account or extending the limit of the emails that can be sent?

I really need to send the survey to all of the participants ASAP. Besides that I will need to send shorter surveys to them every friday from 28 april till 29 may. 

Please help me.