Customer.io outage, 4 September 2026

Reduced Deliverability to Microsoft-Hosted Email Addresses

Started
Resolved
4 Sept 2026, 13:35 UTC (after 1 h 19 min)
Impact
Not stated
Affected
Message Sending

Last update from Customer.io

Microsoft has resolved the underlying issue, we are seeing deliveries to their services resume as normal. Earlier bounces will be retried accordingly. We appreciate your understanding and please do reach out to support if you need any further assistance.

4 Sept 2026, 13:35 UTC

Read the full incident on the official Customer.io status page

Is Customer.io down now?

This page is the record of one past incident. For the live status, see Is Customer.io down right now? - it reads the official status page every 2 minutes.

Other Customer.io incidents

  1. Some US customers may experience delays in message sending

  2. Investigating issues with the Agent

  3. Customer.io UI is inaccessible

  4. Delays in processing and UI inaccessible for some customers in the US datacentre

  5. Issues accessing EU accounts

  6. Some EU users are experiencing delays in processing

  7. Some customers are experiencing data processing and message-sending delays

  8. Delays in message sending

All recorded Customer.io incidents