On June 14, 2021, at ~9:09 pm UTC, Microsoft indicated that they were investigating a Microsoft Teams issue impacting PSTN calls, with Australia as the impacted region. The service incident number was TM262155.
On June 11, 2021, at ~3:02 pm UTC, Microsoft began reporting a Microsoft Teams issue in which incoming calls were being sent straight to voicemail.
Approximately an hour later, Microsoft was reporting on issue identification and a remediation effort (rollback) was underway.
On June 10, 2021, at ~10:21 am UTC, Microsoft was reporting a Teams issue impacting North America.
Twitter responses soon followed confirming the impact was global. Users were confirming impacts to EMEA, APAC, and South America.
On May 26, 2021, at ~6:31 am UTC, Microsoft stated they were investigating an Exchange Online issue in which users were unable to forward email. However, the exact geos impacted were not immediately confirmed and Microsoft suggested that the impact could be for any user of Exchange Online.
On May 11, 2021, at ~4:04 pm UTC, Microsoft stated they were investigating an email message visibility issue in Outlook.
Many on Twitter immediately voiced their frustrations. The issue was confirmed to be of global impact and was already causing significant business disruptions.
On May 10, 2021, at ~1:20 pm UTC, Microsoft was reporting that they were investigating several issues, namely an issue as to email flow.
Twitter first responders were quick to confirm significant issues, of varying sorts, impacting varying geos, as to Microsoft 365 / Outlook emails and email quarantining.
On May 4, 2021, at ~9:52 am UTC, Microsoft reported an unspecified issue with Power Apps and Power Automate. Twitter users responded confirming impacts to at least the North/South American geos.
Approximately an hour later, Microsoft was able to identify the issue (timeout errors within caching components) and a restart/reroute was being performed as the investigation continued.
On April 29, 2021, at ~5:44 am UTC, Microsoft reported an issue with the video and audio quality of Microsoft Teams meetings which were impacting EMEA users.
Twitter responses were as expected, given the Microsoft Teams issue just two days ago (April 27).
On April 27, 2021, at ~6:30 am UTC, Microsoft reported an issue with Microsoft Teams impacting users in Europe and Asia.
Twitter users globally quickly responded, confirming the Teams outage, the Teams app crashing, and the breadth of the impact could perhaps be global and not limited to the Europe and Asia geos.
On April 22, 2021, at ~2:55 pm UTC, Microsoft reported a potential Exchange Online mailflow incident impacting users in North America.
Many Twitter users soon chimed in stating that this "potential" issue was in fact a real issue for their organization.