Update - Following our last update, timeout rates continued to improve but had not fully returned to normal. We submitted a support ticket with OVHcloud and escalated it to the highest priority.

While we have not yet received a response or confirmation of resolution from OVHcloud support, all relevant metrics have now returned to normal levels on our side.

We will continue to monitor closely. Once OVHcloud confirms the issue is fully resolved, we will mark this incident as resolved as well.

May 05, 2025 - 12:48 PDT
Update - As part of their incident mitigation efforts, OVHcloud appears to have made significant changes to their DNS records. In response, we cleared all relevant DNS caches and restarted our servers to ensure the most up-to-date routing information is in use.

Since these changes, IMAP connectivity has largely stabilized and timeout rates have decreased overall. However, we are still actively tuning connectivity to certain OVHcloud servers and will continue monitoring closely.

Apr 30, 2025 - 10:42 PDT
Update - OVHcloud has reported that the network incident impacting their Madrid and Paris points of presence has been resolved.

Start Time: April 28, 2025, at 8:08 AM PT
End Time: April 28, 2025, at 3:00 PM PT
Root Cause: Regional power outage affecting Spain and Portugal.

While OVHcloud has closed their incident, we continue to observe occasional IMAP timeouts. We are closely monitoring the situation and will provide further updates if necessary.

Thank you for your continued patience and understanding.

Apr 29, 2025 - 08:35 PDT
Update - OVHcloud has provided an update on their ongoing incident. Their Madrid Point of Presence (PoP) became accessible again at approximately 2:40 PM Pacific Time. However, they are still experiencing peering issues, which may continue to impact connectivity.

The provider’s teams are actively working to fully restore service. We are continuing to monitor the situation and any potential impacts to IMAP connectivity. Further updates will be posted here as we learn more.

We appreciate your patience and understanding.

Apr 28, 2025 - 15:55 PDT
Monitoring - Starting at approximately 1:30 AM Pacific Time, we began observing elevated timeouts when connecting to the third-party IMAP provider, OVHcloud. OVHcloud has reported an active incident related to widespread power outages across Peninsular Spain and other regions.

We are actively monitoring this situation and any related impacts on email service providers. Updates will be posted here as more information becomes available.

Apr 28, 2025 - 09:00 PDT

About This Site

Seeing issues that aren't reflected on this page? Contact us at support@nylas.com

Nylas Application Services Operational
API v3 ? Operational
Authentication v3 ? Operational
Dashboard v3 ? Operational
Scheduler v3 ? Operational
Webhooks v3 ? Operational
IMAP v3 ? Operational
Data Connectors v3 Operational
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Operational
Degraded Performance
Partial Outage
Major Outage
Maintenance
May 6, 2025

No incidents reported today.

May 5, 2025

Unresolved incident: [EU] Elevated IMAP Timeouts for Email Service Provider OVHcloud.

May 4, 2025

No incidents reported.

May 3, 2025

No incidents reported.

May 2, 2025

No incidents reported.

May 1, 2025

No incidents reported.

Apr 30, 2025
Apr 29, 2025
Apr 28, 2025
Apr 27, 2025

No incidents reported.

Apr 26, 2025

No incidents reported.

Apr 25, 2025

No incidents reported.

Apr 24, 2025

No incidents reported.

Apr 23, 2025

No incidents reported.

Apr 22, 2025
Resolved - Update on Microsoft's Graph API Fix

The issue impacting the sending of emails with large attachments via the Graph API using multipart/form-data due to a Microsoft bug has been addressed. It appears the fix is now fully rolled out, and there have been no errors of this specific type in over 12 hours in both the US and EU regions.

We are confident that the issue has been resolved, but we will continue to monitor the system to ensure stability.

Thank you for your patience throughout this incident.

Apr 22, 17:38 PDT
Monitoring - Update on Microsoft's Graph API Fix

We are seeing significant progress with the fix rolled out by Microsoft for their issue impacting the sending of emails with large attachments via the Graph API using multipart/form-data. Over the past 48 hours, the error rate has dropped substantially, and we are monitoring the improvements closely.

US Region: The error rate has decreased to 0.047% over the past 24 hours.
EU Region: The error rate has decreased to 0.060% over the same period.

We will continue to monitor the situation and provide updates as needed. Thank you for your patience as Microsoft works to fully deploy the fix.

Apr 20, 19:18 PDT
Update - Update from Microsoft:

The cause of the issue has been identified, and a fix has been rolled out. It is expected to be fully deployed by early next week. We apologize for the disruption this has caused.

We will continue to monitor the situation and provide further updates as needed. Thank you for your patience.

Apr 18, 12:11 PDT
Update - To mitigate Microsoft's bug that only impacts attachments sent using multipart/form-data, we recommend using application/json instead for attachments under 3MB. This workaround will continue to work effectively even after Microsoft resolves their bug.

For more details, please refer to Nylas’ official guide:
Sending attachments < 3MB via JSON (Nylas API v3)

Apr 18, 10:34 PDT
Update - We have escalated the bug ticket to the highest priority with Microsoft Office 365. However, at the time of this update, they have only acknowledged receipt of the issue. We are actively working to get a response and status update from Microsoft, but they have yet to make a public acknowledgment.

The number of users and organizations reporting these errors—particularly when sending larger attachments via the Graph API—on public Microsoft forums continues to rise. For reference, here is one of the public threads:

https://learn.microsoft.com/en-us/answers/questions/2258885/graph-api-createuploadsession-returns-401-on-uploa

At Nylas, we are exploring potential solutions to help mitigate these errors for our customers while Microsoft works on a fix. We will update this page as soon as we have progress to share.

Apr 18, 09:06 PDT
Update - We are still waiting on a response from Microsoft to our support ticket, but continue to find other MS Graph users facing the same errors from MS starting today:

https://learn.microsoft.com/en-us/answers/questions/2258994/issue-with-sending-emails-with-large-attachments-v

Apr 17, 12:25 PDT
Identified - We continue to investigate the root cause, however we are starting to see reports around the Internet of other Microsoft Graph users experiencing this net-new behavior and errors from MS. Below is one example:

https://learn.microsoft.com/en-us/answers/questions/2258885/graph-api-createuploadsession-returns-401-on-uploa

We are also opening a Bug Ticket with Microsoft.

Apr 17, 09:46 PDT
Update - We have narrowed the impact of this incident to include only calls to Send for Microsoft Graph for emails with large attachments using multipart/form-data (calls using application/json appear to be unaffected). We are continuing to investigate why Microsoft started returning these provider errors at approximately 1:00 AM today, and why the error messages themselves do not contain any error information.
Apr 17, 05:37 PDT
Update - We are still investigating the cause of this incident.
Apr 17, 04:15 PDT
Investigating - We are investigating higher levels of 401 errors for email sending. This appears to be limited to Microsoft grants sending emails with attachments.
Apr 17, 03:55 PDT