# Shared Mailbox Successful Sign In
Detects Microsoft 365 (M365) shared mailboxes with successful interactive logins in the last 7 days. Many people believe that shared mailboxes can never be logged into and are surprised to learn that when an M365 shared mailbox is created, sign in capabilities are actually enabled by default. Adversaries target these accounts as they typically do not have MFA configured. If they gain access to a shared mailbox, they may assign additional user permissions to the root inbox or other mailbox folders, allowing them to utilize any other account in the tenant to maintain access to the target user's mail folders.
**Recommended Actions**
Review if this was a legitimate login and if this mailbox is meant to have interactive logins.
If there is any unexpected behavior, adjust the mailbox's settings in the Microsoft 365 admin center to block sign-in for the shared mailbox account.
Default Settings:
Evaluation Period (Days): 7
**Compatibility**
[Microsoft Entra ID](/integrations/azure-active-directory-integration.md)
---
# Agent Instructions: Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.
Perform an HTTP GET request on the current page URL with the `ask` query parameter:
```
GET https://docs.oort.io/understanding-check-failures/oort-insights/identity-threat-detection-insights/shared-mailbox-successful-sign-in.md?ask=
```
The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.