If you see the below error messages in Front, they may mean that your email channel in Front is being rate limited by Office 365.

• Failed to send Office 365 temporarily limited our access to your account due to high traffic. Please retry later.

• [email address] is currently experiencing delays due to rate-limiting by Office 365

• Draft failure Unknown SMTP error (o365_error)

If you're seeing a rate limiting error for a channel, it means that the channel is exceeding the number of requests Office 365 authorizes at present. Rate limiting occurs directly on the Office 365 side since they are your actual email provider. These rate limits affect the Microsoft Graph API, which Front and other non-Outlook applications use.

If they are displaying these errors to you, there should also be an accompanying link to tell you more information and how to address it. For more information, see this Office 365 help article about sending limits: Message rate limits and throttling.

We recommend waiting a few minutes before trying to resend messages using Front. This issue will often be resolved over time when your number of requests falls under the exceeding limit. Please do not repeatedly try to resend messages using Front, as this will exacerbate the issue.

If you still need to send messages, you can send them directly from Office 365/Outlook. Once the rate limit issue is resolved you can resume sending messages using Front.

For further assistance, we recommend consulting with Office 365 for tips and any instructions they can offer to help the channel move back to a healthy state.