Nova Fix a Microsoft sign-in blocked by security rules
What to do when Microsoft blocks the sign-in for a mailbox connection because of your company's conditional access, device or location rules.
In the sidebar, open Settings, then choose Email Accounts under Communications (/settings/communications/email-accounts). This screen appears after the Microsoft sign-in step of Connect a Microsoft inbox, when Nova shows Your company's Microsoft security rules blocked this sign-in.
Your company's Microsoft 365 account has rules about who may sign in, from where, and on which devices. One of those rules stopped this sign-in before Microsoft could ask you to approve Nova. Microsoft usually shows a code starting with AADSTS53 on its own page first. Personal Outlook.com, Hotmail, Live and MSN addresses do not have these company rules.
Before you start
Only your company's Microsoft administrator can change these rules. Have the exact message ready for them: open Error details at the bottom of the error screen and select Copy details.
Steps
- Ask the Microsoft administrator to check that the mailbox account is allowed to sign in to connected apps.
- Ask them to review the sign-in rules that apply to email access. Location, device and app rules are the usual causes.
- Have them add an exception for this mailbox, or relax the rule, and save the change.
- If the rule requires a company-managed device, sign in from one.
- Close the browser window, open a new private window, and start Connect a Microsoft inbox again. Start mailbox setup again on the error screen opens the Connect mailbox panel.
What you see
When the rule no longer blocks the account, Microsoft's sign-in goes through to the permissions step and Nova finishes with Connected.
If something looks different
- The screen now says Microsoft needs an extra sign-in check: the rule asks for two-step verification rather than blocking you. See Finish a Microsoft sign-in that asks for two-step verification.
- The screen says Ask your Microsoft administrator: the sign-in worked, but an administrator has to approve Nova. See Get administrator approval for a Microsoft inbox.
- The block comes back after the administrator changed the rule: Microsoft can take a few minutes to apply changes. Wait, then try again from a new private window.