Outage in Sine

Microsoft 365 users seeing delayed email delivery from Sine

Resolved Minor

January 22, 2026 - Started 7 days ago - Lasted about 24 hours
Official incident page

Incident Report

Microsoft is currently experiencing issues affecting Microsoft 365 services, including problems with email delivery to and from Microsoft 365 accounts (Exchange Online). Recent reports indicate a service degradation or outage impacting inbound and outbound email functionality. Users have encountered errors such as "451 4.3.2 Temporary server error" when attempting to send or receive emails, along with intermittent failures in email delivery. Please see https://status.cloud.microsoft/m365/ for more information We will continue to monitor the issue and Sine emails will retry sending at regular intervals

Components affected

Sine Sendgrid Email Gateway

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Latest Updates ( sorted recent to last )

RESOLVED 6 days ago - at 01/23/2026 09:41PM

https://status.cloud.microsoft/m365/ now lists the incident as resolved

INVESTIGATING 7 days ago - at 01/22/2026 10:16PM

Microsoft is currently experiencing issues affecting Microsoft 365 services, including problems with email delivery to and from Microsoft 365 accounts (Exchange Online).

Recent reports indicate a service degradation or outage impacting inbound and outbound email functionality. Users have encountered errors such as "451 4.3.2 Temporary server error" when attempting to send or receive emails, along with intermittent failures in email delivery.

Please see https://status.cloud.microsoft/m365/ for more information

We will continue to monitor the issue and Sine emails will retry sending at regular intervals

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