You got your tenant, add licenses and users and they start using all services. Many settings are to relaxed and you should adjust the configuration for your needs, to enhance security and protect the users from unexpected interactions. Lets walk though some well known and some hidden settings and understand their risk and chance
Microsoft acts like a "drug dealer" and a default tenant is to "open" for most of my customers. But they are not "Secure by Default", because every user can invite guests, create teams, use App Consent, add AzureJoined devices and mich more. German version was presented at Infinity365 in Salzburg
Frank Carius, computer engineer, is the co-founder of the system integrator and software company Net at Work GmbH, located in Paderborn and Berlin. He is one of the few MVPs Skype for Business in Germany. His focus is on consulting and project management in unified communications, particularly the planning, implementation and migration of Microsoft Exchange and Skype for Business, MIcrosoft Teams and Office 365 in general. Frank Carius regularly publishes on the popular website www.msxfaq.de.