Microsoft fixes Outlook ‘Cannot send this item’ email bug

Microsoft has fixed an Outlook bug that blocked users from forwarding or replying to emails containing embedded hyperlinks pointing to long URLs.

Outlook for PC users experiencing this issue are seeing “Cannot send this item” errors according to customers’ reports on Microsoft’s community website.

Others have also pointed out on

Reddit that these errors have also started showing up on long email threads beginning with February.

The issue appears when replying to emails with long links in the body when processed with SafeLinks or when the 2084th character in a link is an escaped character.

Microsoft has fixed the known issue in Outlook for PC build 13913.10000, which should roll out in production Current Channel during late April.

Workaround available until fix goes live

Microsoft also provides a workaround for users affected by this bug until the fix will roll out.

To get rid of “Cannot send this item” errors when replying or forwarding emails in Outlook, you have to do one of the following:

• Change the email format from HTML to Rich text. Go here for more information and detailed steps: Change the message format to HTML, Rich Text Format, or plain text – Outlook (microsoft.com)
• Remove any long links in the body of the email before replying.
• Reply to the email using Outlook Web App (OWA)
• Switch Office to Semi Annual Channel where the bug is not introduced. To do this, follow the steps here: Change the Microsoft 365 Apps update channel for devices in your organization

Microsoft is also currently investigating issues where the follow-up flag status is displayed in sent messages incorrectly and error messages being displayed when sharing a calendar in Microsoft 365.

Last year, Redmond addressed a major issue affecting Microsoft Outlook worldwide with the application immediately crashing on launch with 0xc0000005 errors displayed in the Windows Event Viewer.

Source: https://www.bleepingcomputer.com/news/microsoft/microsoft-fixes-outlook-cannot-send-this-item-email-bug/