We are currently aware of delays affecting the delivery of outbound email to recipients whose domains are hosted on Microsoft 365 / Exchange Online.
When the issue was first detected, our technical team investigated whether Microsoft may have been temporarily throttling or restricting connections from certain Absolute Hosting mail server IP ranges. As a precaution, we proactively logged a case with Microsoft while continuing to investigate the behavior across our mail infrastructure.
We have subsequently confirmed that the issue is not isolated to Absolute Hosting. Microsoft has acknowledged a wider Exchange Online service issue affecting the sending and receiving of email between Microsoft 365 and external mail systems.
Messages affected by temporary Microsoft delivery restrictions will remain queued on our mail servers and will automatically be retried. Customers therefore do not need to resend affected messages, as doing so may result in duplicate delivery once Microsoft's systems accept the queued mail.
Our technical team is actively monitoring outbound mail queues and Microsoft 365 delivery behavior.
We apologize for the inconvenience caused and will continue to monitor the situation until Microsoft confirms that normal mail delivery has been restored.
When the issue was first detected, our technical team investigated whether Microsoft may have been temporarily throttling or restricting connections from certain Absolute Hosting mail server IP ranges. As a precaution, we proactively logged a case with Microsoft while continuing to investigate the behavior across our mail infrastructure.
We have subsequently confirmed that the issue is not isolated to Absolute Hosting. Microsoft has acknowledged a wider Exchange Online service issue affecting the sending and receiving of email between Microsoft 365 and external mail systems.
What this means for customers
Emails destined for Microsoft 365-hosted domains may experience delayed delivery while Microsoft works to restore normal mail flow.Messages affected by temporary Microsoft delivery restrictions will remain queued on our mail servers and will automatically be retried. Customers therefore do not need to resend affected messages, as doing so may result in duplicate delivery once Microsoft's systems accept the queued mail.
Measures we are taking
As a proactive measure, we are increasing the delivery retry period across our outbound mail relays and mail servers. This will allow affected messages to remain queued for longer and continue attempting delivery to Microsoft rather than being returned to the sender prematurely.Our technical team is actively monitoring outbound mail queues and Microsoft 365 delivery behavior.
We apologize for the inconvenience caused and will continue to monitor the situation until Microsoft confirms that normal mail delivery has been restored.
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