Email Issue - While Sending multiple Email ID's

Sending email to multiple email ID’s.
IN my mail box, sent items shown each recipient separately.
Example: if i sent 10 recipient in one mail, In sent items shown 10 Emails.
my problem is due to above, mail box getting full and microsoft block the email due to maximum sending limit reach within hour.
I am using office365.
Kindly expecting support from community.
Thanks in advance.