Delete a O365 suspicious online account?

My previous admin had migrated our exchange from SBS2011 to Office365. Since, he is not here i am handling everything. I found few suspicious account like one SBS8OPEAdmin@…onmicrosoft.com

I can only think of the name that it was related to the old Exchange 2010.

How should I know is this account being used elsewhere or can I get delete it?

Thanks