The December security and rollup update has been made available for all Click-to-Run installations of Outlook 2016, Outlook 2019, Outlook 2021, Outlook 2024, and Outlook as part of a Microsoft 365 subscription.
It contains 5 security updates for Access (1), Excel (1), Project (1), and Shared Office Components (2).
In addition, it contains 1 non-security fix related to Outlook Current Channel Version 2411, 12 fixes related to Outlook Monthly Enterprise Version 2410, and 6 fixes related to Semi Annual Preview Version 2408.
- Version 2411
- Resolved an issue in Word and Outlook where characters didn’t render correctly when using “Save Selection to Text Box Gallery”. (Word)
- Version 2410
- Resolved an issue in Outlook where content may not be visible in the email body unless using Forward or Reply.
- Resolved an issue where all characters may not appear correctly when creating an Outlook task from OneNote.
- We fixed an issue where content marking wasn’t working for HTML messages when SMIME was enabled.
- We fixed an issue in Outlook where mail from a profile activated and directed to a different portal was being redirected to https://portal.microsoft.com.
- We resolved an offline address book (OAB) download issue by adding a registry key to give the BITS jobs for automatic (non-manual) OAB downloads the same priority as the BITS jobs for manual (user-initiated) OAB downloads.
- We fixed an issue that caused users with a large number of folders expanded during synchronization to experience a non-delivery receipts (NDRs) with the failure MAPI_E__TOO_BIG (0x80040305).”
- We fixed an issue where adding an Outlook or a Hotmail account to a mail profile nullified a policy preventing copying messages between exchange stores.
- We fixed an issue where a meeting request received by an Exchange account would appear with a blank body in Outlook Desktop cached mode.
- We fixed an issue where opening an .ICS attachment from a email shows security prompt.
- We fixed an issue where Do Not Forward (DNF) was left on message when applying and removing label.
- We fixed an issue that caused the Wait on Send experience to stop working until the user clicked “Send Anyway.”
- We fixed an issue where the accessibility mail tip kept appearing and disappearing, causing the content to jump when composing an email.
- Version 2408
- Users who switch to the New Outlook for Windows will see the web equivalents of their current add-ins enabled on the new client where available.
- We fixed an issue where the Wait on Send experience didn’t complete until the user clicked “Send Anyway.”
- We fixed an issue that caused users who were replying to a message with an Information Rights Management policy applied to see the error “You don’t have permission to make this change to the sensitivity label” when no label changes were made.
- We fixed an issue that caused users to see emails that they forwarded from their sent items folder be sent with a label applied but no protection when the mail being forwarded was originally sent from Outlook running on a different platform.
- Resolved an issue in Outlook where unexpected characters may appear in comments when using the setting “Preface comments with” and the Aptos font. (Word)
- We made a change to enable Nested App Authentication for Outlook add-ins. (Office)
Current versions and build numbers
Based on your release channel, you’ll be updated to the following version;
- Microsoft 365 Apps, Outlook 2016 Retail, Outlook 2019 Retail, Outlook 2021 Retail, Outlook 2024 Retail
Version 2411 (Build 18227.20162) - Monthly Enterprise
Version 2410 (Build 18129.20200)
Version 2409 (Build 18025.20242) - Semi-Annual Enterprise (Preview)
Version 2408 (Build 17928.20336) - Semi-Annual Enterprise
Version 2402 (Build 17328.20670)
Version 2308 (Build 16731.20998) - Outlook LTSC 2024
Version 2408 (Build 17932.20190) - Outlook LTSC 2021
Version 2108 (Build 14332.20828) - Outlook 2019 Volume Licensed
Version 1808 (Build 10416.20027)
Note: Depending on your installation type, this update can be installed via the Update Now button in Outlook itself or the Microsoft Store. This update does not apply to msi-based installations of Office 2016.
Outlook’s indexed search is fast as long as you know the exact beginning of the word or string that you are looking for.
Thinking about upgrading your computer to Windows 11 or are you using Outlook on a Windows 11 computer already and are being offered 
When you reply to an email in Outlook, the original emails are not included. This is because it is assumed that the original sender still has access to the original attachments.
Nowadays, it is quite likely that you have multiple email accounts configured in Outlook.
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When composing a message in the HTML format in Outlook, the HTML code is automatically generated by the WordHTML engine. Unfortunately, Outlook does not provide a direct way of editing this generated HTML code.
Do you need to send the same emails on a recurring basis like daily, weekly or monthly? Sending out reminders, forwarding reports or the latest offers and prices can be a tedious task.
S/MIME support for Outlook on the Web (OWA) used to be only available in Internet Explorer but it is now also possible to add this to Google Chrome and the new Microsoft Edge browser.
There are several guides containing PowerShell scripts on HowTo-Outlook.com. PowerShell is a powerful scripting language which can be used by many applications including Outlook and Exchange. For end-user usage, it can be seen as the successor of vbs and batch scripts.
If you’ve ever used Outlook Express, Windows (Live) Mail, Thunderbird, Lotus/IBM Notes or basically any mail client other then Outlook, chances are that you have some eml-files stored somewhere as well.
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Thinking about upgrading your computer to Windows 10 or are you using Outlook on a Windows 10 computer already and are being offered 
When configuring your Gmail account in Outlook (or other mail clients such as Thunderbird and Mail apps on (older) smartphones), you may run into continuous password prompts or sync errors.
