HomeWinBuzzer NewsMicrosoft: Windows 11 Now Disables Remote Mailslot by Default

Microsoft: Windows 11 Now Disables Remote Mailslot by Default

Microsoft is starting the process to remove Remote Mailslot from Windows 11, which is disabled through new Canary Channel release.


is already putting its new Windows Insider Program Canary Channel to good use with the release of preview build 25314. This build brought plenty of changes, including File Explorer recommendations. However, the fact that Microsoft is removing Remote Mailslot has flown under the radar a little.

The release notes for build 25314 confirm this is happening, but Microsoft has also written a dedicated blog post on the decision. The company's Principal Program Manager Ned Pyle says that Remote Mailslot is a legacy protocol that is now disabled on Windows 11 through the new Canary Channel update.

Pyle adds that it will be shut down fully soon and then completely removed.

“The Remote Mailslot protocol is a very old, simple, unreliable, insecure inter-process communication met… we have started disabling the Remote Mailslot protocol by default. This is a precursor to deprecation and eventual removal from Windows. You aren't using this extremely legacy protocol unless you're also using the deprecated and disabled-by-default SMB1 protocol, so 99.97% of you have nothing to worry about.”


Remote Mailslot is an old protocol that comes from the release of LAN Manager DOS. Yes, that means it predates every version of Windows since 1990. Needless to say, technology has moved on in the following thirty years since the launch release of Remote Mailslot.

Microsoft is now disabling the protocol by default and trying to use it surfaces an error message. If users need Remote Mailslot, Pyle recommends telling your software vendor to “join the 21st century”.

Tip of the day: If you need to Create, Delete or Resize Partitions, Windows has everything you thanks to the built-in Disk Management-tool.

Luke Jones
Luke Jones
Luke has been writing about all things tech for more than five years. He is following Microsoft closely to bring you the latest news about Windows, Office, Azure, Skype, HoloLens and all the rest of their products.

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