Integration with Microsoft 365

This page includes:

About integrating Microsoft 365 email services

You can integrate "Acronis Email Security" with Microsoft 365. This enables "Acronis Email Security" to protect incoming mail into a Microsoft 365 installation. [This refers to Microsoft Exchange Online]

When you integrate "Acronis Email Security" with Microsoft 365, you can select either of the following integration methods:

Inline

Emails are scanned [and can be blocked if they are found to be malicious] before they are delivered to the end-user inbox. Requires adding a TXT record to the DNS and then running an automated onboarding script. Includes a more complex onboarding process. For details, see Step 1 - Onboarding Microsoft 365 [Inline]

Microsoft API

Emails are scanned in parallel with the delivery of the email. The email first arrives in the end-user inbox, and only after scanning, is the email removed if it is found to be malicious. End users may therefore see malicious emails in their inboxes for a few seconds before the email is deleted. Doesn't require a TXT record. Includes a simple onboarding process. For details, see Onboarding Microsoft 365 [API]

Note:

The Microsoft 365 integrations monitor incoming emails only - not outgoing emails.

[Outbound monitoring can be added to inbound Microsoft 365 [Inline and API] integrations - see Onboarding Microsoft 365 - Outbound]
For information about switching between Inline integrations and API integrations, see Switching integrations.

Comparing the Microsoft 365 Inline and API integration methods

The table below should help you to choose the better integration method for your scenario - Inline or API...

	Inline	API scanning
1	Operates in prevention mode: Scans and blocks malicious emails pre-delivery	Operates in detection and remediation mode: Scans emails in parallel with the delivery of the emails
2	More complex onboarding procedure - typically requiring addition of a domain, verifying a TXT record, and running an automation script	Simpler and quicker onboarding procedure - typically requiring just 3 mouse-clicks
3	Requires adding a TXT record to the DNS	Adding a TXT record is not required
5	Adds an extra hop to the email	Scans in parallel and therefore doesn't add a hop
6	End users won’t see any emails with malicious scan verdicts in their Inboxes	End users may see malicious emails in their Inboxes for a few seconds - before the scan is completed and the email is quarantined
7	Supports hybrid environments [Exchange Online and Exchange On-Prem]	Supports only Microsoft 365 environments [Exchange Online]
8	Supports billing for full protection of a Microsoft 365 account - not partial protection	Supports billing for full or partial protection of a Microsoft 365 account
9	Allows remediation	Allows remediation
	For details, see Step 1 - Onboarding Microsoft 365 [Inline]	For details, see Onboarding Microsoft 365 [API]

[Inline vs API]

Maximum email sizes for scanning

Microsoft 365 Inline integrations

"Acronis Email Security" scans email messages up to a maximum size of 40 MB [including attachments]. Larger email messages are not scanned by "Acronis Email Security", and will be delivered to the specified recipients.

Note:

Due to external technical limitations, the 40 MB limitation can't be increased.
We recommend that you limit receiving email attachments up to 30 MB in size. Files that are larger than 30 MB should be shared using a different file sharing service, such as Microsoft OneDrive or Google Drive.

Microsoft 365 API integrations

"Acronis Email Security" scans email messages up to a maximum size of 500 MB [including attachments].

Other Microsoft 365 integration options

If you have integrated "Acronis Email Security" with Microsoft 365, you can enable the additional "Acronis Email Security"-Microsoft 365 ATO [account take over] functionality. This functionality monitors your Microsoft 365 accounts to detect if any of them have possibly been taken over. For details, see Configuring Microsoft 365 - ATO detection.