Ensured reliable email delivery for Microsoft 365 accounts

We resolved a critical bug that affected users sending emails through their own custom Microsoft 365 SMTP configurations. The authentication token required to connect to Microsoft's services was expiring and not being refreshed, causing email deliveries to fail silently.

This issue could interrupt key workflows, such as sending candidate invitations, and negatively impact the hiring process. The fix ensures the authentication token is now proactively refreshed, guaranteeing reliable email delivery for all users with a custom Microsoft 365 email setup.