Вот некоторые большие ответы и обеспеченные указатели:
Someone posted a small patch to allow customizing the server port to the Emacs Bugs list in September 2008. However, the patch didn't make it into Emacs 23.1 nor does it appear in CVS Emacs as of yet. Your best bet for now might be to patch your version of server.el
locally.