Config smtp office365 for send mailing campaigns

I need to configure one account or many accounts for SMTP in my office365 to send mailing campaigns of 15k ~ 30k emails daily. I read that with one account with smtp I can send 10k emails daily, I tried to send 5k with one account but it dont sent all emails. So I want try with more than 1 account. So I need that you teach me to config 1 account for use smtp from external software and I will config the rest. If you have experience doing mailing campaigns with office365 or you have a better idea please send me details in your proposal and I will chat as soon as possible.

Thanks you !