I don’t really know anything about this but given our use of old hardware and software, I thought it was worth the share:
Microsoft Blog Post
Quote
With the release of Windows 11 Insider Preview Build 25314, 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.