When connecting an Microsoft 365 mailbox to Kolleno, the integration uses Microsoft OAuth 2.0 a secure, token-based authentication method. This means Kolleno receives permission from Microsoft to access your mailbox without storing or repeatedly using your password.
This article explains how multi-factor authentication (MFA), sign-in restrictions, and dedicated mailbox security practices work with Kolleno to keep your email integration secure and reliable.
How OAuth Authentication Works
Kolleno connects to your mailbox using Microsoft's OAuth 2.0 authorisation flow, not by storing your password.
What this means:
During the initial connection, you (or your admin) complete Microsoft's sign-in and consent process
Microsoft issues access tokens and refresh tokens to Kolleno
Tokens are managed securely by Microsoft and can be revoked at any time by your IT admin
Is Multi-Factor Authentication (MFA) Supported?
Yes. MFA is fully compatible with Kolleno and is recommended for security.
How MFA Works with Kolleno
During Initial Connection or Re-authentication
When you first connect your mailbox, you may be prompted to complete MFA (e.g., approve via authenticator app, SMS code)After Connection
Once connected, Kolleno operates using the Microsoft-issued tokens.
Can I Disable Sign-in on the Mailbox? Will That Break Kolleno?
We do not recommend fully disabling sign-in for the integration mailbox.
Why Sign-in Access is Required
Even though Kolleno doesn't perform daily interactive sign-ins, Microsoft may require sign-in to be available for:
Token refresh or renewal
Re-authentication
Security events
If sign-in is completely blocked, you may be unable to complete the required re-authentication, and the connection will fail until sign-in is restored and the mailbox is reconnected.
How to Secure the Mailbox Account
Best Practices:
Use a Dedicated Mailbox for Kolleno
Create a mailbox specifically for the integration (e.g.,ar-integrations@yourcompany.comornoreply@yourcompany.com), rather than using a personal or shared mailboxEnable Multi-Factor Authentication (MFA)
MFA protects the initial authorisation and any future re-authentication eventsAvoid Sharing Credentials
Only the person performing the initial connection needs the mailbox password. After connection, operational access is managed via tokens, not credentials