Update -
We have acknowledgment from Microsoft about the change in delivery behavior on their consumer email platform. Microsoft has acknowledged that the behavior is not isolated to SendGrid's environment and is not specific to our sending configuration.
Our engineering team is seeing improvement (reduction) of deferrals since the start of the incident on 1/14. Blocks have also reduced but are still at elevated levels; we will keep monitoring the behavior.
Customers that feel they are continuing to observe excessive deferrals and/or blocks should fill out the OLC Support request form at https://olcsupport.office.com/
Jan 27, 2026 - 16:05 PST
Monitoring - Our engineers continue to work with Microsoft and will provide additional details and guidance shortly.
Jan 27, 2026 - 15:24 PST
Update - Our engineering team is still actively investigating this issue, and we will provide more updates as soon as they become available.
Jan 27, 2026 - 08:00 PST
Update - Our engineering team is still actively investigating this issue, and we will provide more updates as soon as they become available.
Jan 26, 2026 - 07:56 PST
Update - Our engineering team is still actively investigating this issue and we will provide more updates as soon as they become available.
Jan 24, 2026 - 10:55 PST
Update - Our engineering team is still actively investigating this issue and we will provide more updates as soon as they become available.
Jan 23, 2026 - 15:35 PST
Update - Our engineering team is still actively investigating this issue and we will provide more updates as soon as they become available.
Jan 23, 2026 - 08:00 PST
Update - Our engineering team is still actively investigating this issue and we will provide more updates as soon as they become available.
Jan 23, 2026 - 03:22 PST
Update - Our engineering team is actively investigating this issue and we will provide more updates as soon as they become available.
Jan 22, 2026 - 16:18 PST
Investigating - Starting around 3:00 am PST on January 14, our engineers began investigating an issue with emails sent to Microsoft Outlook Consumer domains. Some customers may experience an increase in email block rates to Microsoft Outlook Consumer domains which include Hotmail and Outlook domains. Our Engineers are working with Microsoft. We will provide another update in two hours or as soon as more information becomes available.
Jan 22, 2026 - 14:07 PST