This is similar to Linus Torvalds's (former?) practice of "dropping patches" in response to overload.
It's actually not a bad queue management process overall. Local processor offline / overloaded? Drop all but the very highest priority (for email: immediate family, $BOSS) messages.
The late Joe Barr describes this obliquely in his discussion of the development of BitKeeper (git's predecessor as the Linux kernel code repository):
http://joebarr.sys-con.com/node/32618/mobile
It's actually not a bad queue management process overall. Local processor offline / overloaded? Drop all but the very highest priority (for email: immediate family, $BOSS) messages.
The late Joe Barr describes this obliquely in his discussion of the development of BitKeeper (git's predecessor as the Linux kernel code repository): http://joebarr.sys-con.com/node/32618/mobile