---
title: "Troubleshooting Microsoft 365 Email Integration & Notification Issues"
description: "This troubleshooting guide helps you identify and resolve common Microsoft 365 email integration errors to ensure your notification workflow remains uninterr..."
url: "https://help.staticso2.com/user-integrations/ms-office365-calendar-connection/troubleshooting-microsoft-365-email-integration-notification-issues"
---

This troubleshooting guide helps you identify and resolve common Microsoft 365 email integration errors to ensure your notification workflow remains uninterrupted.

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## Mail Send Permission Removed

[Section titled “Mail Send Permission Removed”](#mail-send-permission-removed)

### Symptoms:

[Section titled “Symptoms:”](#symptoms)

* The User (Administrator/ Member) will receive an error notification when the Microsoft 365 mail sending permission is revoked on their account by IT.
* Guests will stop receiving any booking-related email notifications or calendar invites.

### Cause:

[Section titled “Cause:”](#cause)

The **Mail.Send** permission for the OnceHub application has been revoked in Azure AD. Once revoked, OnceHub cannot send emails on behalf of the user.

### Resolution:

[Section titled “Resolution:”](#resolution)

The easiest way to restore the permission is to re-establish the connection.

1. Click on your **profile picture** in the top right-hand corner.
2. Select **User Integrations**.
3. **Disconnect** and **Connect** your Microsoft 365 account.

**NOTE:** While disconnecting and reconnecting the account, ensure that full email permissions are granted either by the User or on behalf of the organization.

***

## Mailbox Quota Exceeded

[Section titled “Mailbox Quota Exceeded”](#mailbox-quota-exceeded)

### Symptoms:

[Section titled “Symptoms:”](#symptoms-1)

* The User (Administrator/Member) will receive an error notification when their mailbox storage quota is full.
* Guests will not receive any booking-related email notifications or calendar invites until storage space is freed.

### Cause:

[Section titled “Cause:”](#cause-1)

The User’s Microsoft 365 mailbox has reached its storage limit or exceeded its sending quota, preventing OnceHub from sending notifications.

### Resolution:

[Section titled “Resolution:”](#resolution-1)

To fix this issue, the Microsoft 365 Workspace Administrator responsible for managing mailbox settings should follow these steps:

1. Go to the Microsoft 365 Admin Center.
2. Navigate to **Users → Active Users → \[Select the User] → Mail** tab.
3. Review the current storage and quotas. For detailed Microsoft guidance on managing storage, see[ **Mailbox Storage Quotas**](https://learn.microsoft.com/en-us/Exchange/recipients/user-mailboxes/storage-quotas).
4. **Retry** sending notifications from OnceHub.