EFS does not depend on VM. One file, efs-vm.el, contains a bunch of copied and hacked VM functions that allow you to use FTP to (somewhat clumsily) retrieve your e-mail. This code calls a bunch of VM internal functions and macros, which means VM has to be present at compile time and run time. If you removed this efs-vm.el from the EFS package, EFS would keep right on working. Given the widespread availability of POP and IMAP, both of which VM can use to retrieve messages, I doubt if there is anyone, including Sandy Rutherford, who is still using this code. So my first choice would be to bury this code and get rid of the bogus dependency that way. Failing that, move efs-vm.el to a separate package. Last and worst option, change the require from 'vm to 'vm-autoload.