Office 365


Acronis True Image 2019 アップデート 2(ビルド 14610)以降では、MS Microsoft 365 一般消費者アカウントの OneDrive およびメールボックスをバックアップできます。バックアップは Acronis クラウドに保存されます。この機能を利用するために、Acronis True Image Advanced または Premium サブスクリプションが必要です。

(!) Microsoft 365 ビジネスアカウントのバックアップはサポートされません。Microsoft 365 ビジネスアカウントをバックアップするためには、Acronis Backup の使用を推奨しています。

ご自分の メールボックスにおいてバックアップできるデータ:

Comparison of Microsoft 365 protection options with local Agent for Microsoft 365 and Cloud-based Agent for Microsoft 365 in Acronis Cyber Protect 15 and Acronis Cyber Backup 12.5. To learn more about on-premises and cloud deployment see product documentation.

(!) The table describes features available in Acronis Cyber Backup 12.5 Update 3 (Build 11010) and later. Some features are unavailable in earlier builds.


  1. You have installed an Agent for Microsoft 365 on a Windows machine or added a C2C agent, and created a plan for backing up Microsoft 365 mailboxes,
  2. Backup of Microsoft 365 mailboxes finishes with errors:

    SOAP protocol error has occurred while accessing the EWS server. SOAP code: ErrorNonExistentMailbox. SOAP message: The SMTP address has no mailbox associated with it


Microsoft 365 mailbox has Not protected status although a group backup plan is applied.


Issue happens because currently C2C agent does not perform backup of O365 mailboxes that do not have a valid license.

You backed up a private channel in Microsoft Teams. Later, you deleted the channel and want to restore it from the backup.

Restore fails with this error:

A backup agent error: 'Channel Channel id=<id> was not restored

Files folder of Channel id=<id> is not ready. Recovering of Channel's messages impossible

You run a backup of Microsoft Office 365 mailbox and/or OneDrive with Acronis True Image 2019/2020
Backup fails with the following error:

Cannot back up this mailbox because the login for the account to which the mailbox belongs is also used for another Microsoft account


You log in the Protection Console as a customer group company administrator and attempt to add a Microsoft 365 organization as described in the User Guide.

This leads to a download prompt for the local agent for Microsoft 365 instead of redirecting to the Microsoft 365 login page.


The behavior is expected if the tenant has "Enhanced security" enabled.


Starting from Acronis True Image 2019 Update 2 (Build 14610) you can back up OneDrive and mailboxes for Microsoft 365 Consumer accounts. Backups are saved to Acronis Cloud. You need Acronis True Image Advanced or Premium subscription to use this feature.


Backup, recovery, or other operations with Microsoft 365 items fail with the following error:

.NET exception 'System.Net.WebException' has occurred: The underlying connection was closed: An unexpected error occurred on a send

This applies both to C2C backup and to local Agent for Microsoft 365.


Legacy editions are in use.

There are enough Microsoft 365 seats in the offering items, but the backup still fails for shared mailboxes with the following error: 

The following quota is reached for <...> : Number of protected Microsoft 365 seats.


Issue in the product: impossible to protect non-personal Microsoft 365 resources in legacy editions.