Account blocked mail rate limit

Account blocked mail rate limit

my account is blocked, seemingly due to exceeding the mail rate limit 

Can it be unblocked please

What is the limit? I have only sent 5 emails, each with about 20 recipients. I'm simply trying to send out my organisation's newsletter and I thought doing it in batches would prevent problems with spam filters

The address is newsletter@emmausnewslettersa.org