Why can't I send or receive large attachments in Outlook anymore?

Hi @Savage Wilson

Thanks for using Microsoft product and posting in the Microsoft Q&A.

It is exactly as @Arlene D has mentioned that Outlook has a default limit for attachments. However, it can be changed in the Windows Registry. This is a very specific solution, so follow the steps exactly.

1. Close Outlook completely.
2. Open the Windows Start Menu and type regedit. Right-click on the regedit program and select Run as administrator.
3. Navigate to the following registry key:HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Preferences(Note: The "16.0" in the path is for Outlook 2016, 2019, and Microsoft 365. If you have an older version, the number might be different, e.g., 15.0 for Outlook 2013.)
4. Right-click on the Preferences folder, select New, and then choose DWORD (32-bit) Value.
5. Name the new value MaximumAttachmentSize.
6. Double-click on the new MaximumAttachmentSize value.
7. In the "Value data" field, enter the desired maximum size in megabytes (MB), not bytes. For example, enter 50 to set a 50MB limit. Enter 0 to remove the limit entirely.
8. Click OK and then close the Registry Editor. When you restart Outlook, the new attachment size limit will be in effect.

Please let me know how these suggestions work for you, or if you'd like further assistance.

==========================================================

To assist others who might have similar questions and to help us improve our support system, we kindly encourage you to "Accept the answer" if it successfully addressed your concern. Accepting an answer lets other users know that this solution worked for you, and it also helps us track the effectiveness of our support efforts.