e-mail: revive dead code that checks for unspecified recipients Commit 609e06b6c52f6a8ea9581372805c4bbb60db81a1 introduced dead code: in the beginning of send_email an assert verifies that recipients is of type 'list', so checking it for None later is useless and that branch can never be reached. Instead of removing the dead code, revive it and add a test case.