Can I see who has logged into my Office 365 account?
Login history can be searched through Office 365 Security & Compliance Center. In the left pane, click Search & investigation, and then click Audit log search. Please notice that for User activity in Exchange Online (Exchange mailbox audit logging) you need to have mailbox audit logging turned on for each user.
Does Microsoft send security alerts?
Microsoft prioritizes account security and works to prevent people from signing in without your permission. When we notice a sign-in attempt from a new location or device, we help protect the account by sending you an email message and an SMS alert.
How do I set up an activity alert in Office 365?
Login to Office 365 admin portal and browse to Security & Compliance Center. Expand Alerts and select Alert Policies. Manage Activity Alerts section is not listed at first. To get to the management portal you will need to create an Activity Alert first via PowerShell.
What causes suspicious email sending patterns detected?
Suspicious email sending patterns detected
Generates an alert when someone in your organization has sent suspicious email and is at risk of being restricted from sending email. This is an early warning for behavior that may indicate that the account is compromised, but not severe enough to restrict the user.