upgrade zonemta and compress backup only once, also remove needless files

v20231216.1

bug missing client dir

compress autobackup with xz

v20231208.2

compress backup with xz

allow relay host with login for zoneMTA

v20231208.1

add relay host environment variables

backup all files and increase mail size to 100MB

v20230910.1

backup all files and increase mail max size to 100MB

v20230511.1

build v20230511.1

v20230510.2

build v20230510.2

v20230510.1

build v20230510.1

v20230509.5

build v20230509.5

v20230509.3

build v20230509.3

v20230509.2

build v20230509.2