Reply To: Outlook Not Sending Emails Error 10 Proven Methods to Fix it

[Sid Heart]

#1945960

Based on the symptoms you described, this looks like a combination of a problematic Microsoft 365 update and profile or data file instability on a Terminal Server environment. Outlook crashes after updates are often related to cached mode issues, corrupted local OST or PST files, or conflicts introduced by recent builds.

Before waiting for Microsoft to recall or patch the update, a few practical steps usually help narrow it down:

Temporarily disable Cached Exchange Mode and test Outlook in online mode

Create a fresh Outlook profile and reattach the mailbox

Check disk health on the server, as even minor disk errors can corrupt Outlook data files

Roll back to the previous stable Microsoft 365 build if possible in your update channel

If the mailbox data itself is suspected to be unstable, exporting or moving email data off the affected profile can help prevent further crashes. In cases where Outlook becomes unusable, accessing the mailbox through a controlled imap mail transfer process can allow you to safely move data to a clean mailbox or server without relying on the broken Outlook profile.

This approach is especially useful in terminal server setups where repeated crashes impact multiple users. Once the data is secured, Outlook can be rebuilt cleanly or migrated to a stable environment after Microsoft releases a fix.

Hopefully Microsoft addresses this build quickly, but protecting the data first is the safest move.