Outlook/Office365 Issues

This guide covers the two most common issues when connecting an Outlook/Microsoft 365 mailbox to Acculeo, and how to resolve them.

Contents

1. "Needs admin approval" – missing administrator consent
2. Connection fails because IMAP is not enabled on the mailbox

Issue 1: "Needs admin approval" – missing administrator consent

When you try to connect the mailbox, Microsoft shows "Needs admin approval", even after an administrator has approved access.

Cause

Microsoft distinguishes between two different services:

• Microsoft Graph – Microsoft's general API.
• Office 365 Exchange Online – the service that controls mailbox access (including IMAP).

Acculeo requests the IMAP.AccessAsUser.All permission under Office 365 Exchange Online. If the admin consent was only granted under Microsoft Graph, it does not cover mailbox access, and Microsoft will keep requiring admin approval.

Solution: The administrator must approve the Acculeo app

Your Microsoft 365/Entra administrator needs to do the following once:

1. Sign in to the Entra Admin Center as Global Administrator.
2. Go to Applications → Enterprise applications.
3. Search for and select Acculeo.
4. Click Permissions in the left menu.
5. Click the "Grant admin consent for [your company name]" button at the top of the page and confirm.

This approves the permissions Acculeo requests – including mailbox access via Office 365 Exchange Online (IMAP.AccessAsUser.All). After the approval, the permissions must show "Granted for [your company]".

Important: The correct account must complete the connection

Once consent is in place, the connection in Acculeo must be completed by the mailbox owner – e.g. invoices@ – not the administrator. Microsoft issues access to whichever account signs in at the login window. If the administrator completes the login flow, the administrator's own mailbox gets connected instead.

In Microsoft's login window you can explicitly select the correct account (e.g. invoices@). Using a private/incognito window is recommended if you are already signed in with the administrator account.

Issue 2: Connection fails because IMAP is not enabled on the mailbox

If the approval succeeds but the connection still fails with an authentication error, the cause may be that IMAP is disabled for the mailbox in Microsoft 365.

Solution: Enable IMAP on the mailbox

1. Sign in to the Microsoft 365 Admin Center as administrator.
2. Go to Users → Active users.
3. Find and click the relevant e-mail account (e.g. invoices@yourcompany.com).
4. In the panel that opens on the right, select the Mail tab.
5. Under Email apps, click Manage email apps.
6. Make sure IMAP is checked.
7. Click Save changes.

Note: The change can take up to 15 minutes to take effect.

Still having problems?

If the connection still fails after both steps, please contact Acculeo support and provide:

• The mailbox you are trying to connect.
• The time of the failed attempt.
• Any error text from Microsoft.