Postmortem -
Read details
Mar 5, 04:46 EST
Resolved -
Between February 26 and February 28, Microsoft filtering behavior caused intermittent delivery issues for email invites sent to Microsoft-hosted domains (Outlook, Hotmail, Live, Microsoft 365).
SignNow systems were operating normally, and messages were successfully transmitted and accepted by Microsoft servers. The disruption occurred within Microsoft’s filtering layer due to aggressive spam detection behavior.
Microsoft has identified the issue and is applying backend mitigation (whitelisting) while continuing to tune their detection models.
While awaiting final confirmation from Microsoft, we are proactively re-sending affected unsigned invites to impacted recipients to ensure successful delivery.
We are continuing to monitor delivery behavior closely and will provide updates if needed.
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Microsoft confirmed that fix was aplied globally and invites has to be delivered with no further issues.
SignNow team will resend all unsgned invites shortly.
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SignNow team has resent all affected emails invites.
Mar 1, 16:55 EST
Update -
We are currently awaiting confirmation from Microsoft that the applied fix has been successful.
Mar 1, 07:21 EST
Monitoring -
This incident was caused by aggressive spam filtering behavior within Microsoft-hosted email environments (Outlook, Hotmail, Live, Microsoft 365).
SignNow systems were functioning correctly and emails were successfully accepted by Microsoft servers (SMTP 250 OK). However, Microsoft’s filtering layer intermittently flagged and quarantined certain messages before reaching recipient inboxes.
Microsoft has acknowledged the filtering behavior and applied backend whitelisting for signnow.com as an interim mitigation while tuning their detection models.
The issue is currently mitigated and under monitoring.
Feb 28, 12:59 EST
Update -
We are still investigating intermittent email delivery issues affecting recipients on Microsoft-hosted domains (including Outlook.com, Hotmail.com, Live.com, and Microsoft 365/Exchange Online environments).
Some emails sent from SignNow to Microsoft-hosted mailboxes are being accepted by Microsoft servers but may not reach the recipient’s inbox. In certain cases, messages may be silently filtered or quarantined.
Feb 28, 12:29 EST
Identified -
The issue has been identified and a fix is being implemented.
Feb 27, 13:14 EST
Update -
Issue with sms invites is now being fixed.
Email invites still might be routed to spam folders.
Our team is actively investigating the issue and will provide updates as they become available.
Feb 27, 12:56 EST
Investigating -
Some users may experience issues with SMS invite delivery. Additionally, email invites may be routed to spam folders.
Our team is actively investigating the issue and will provide updates as they become available.
Feb 27, 11:45 EST
