To enable PPTP server:
[admin@MikroTik] interface pptp-server server> set enabled=yes
[admin@MikroTik] interface pptp-server server> print
enabled: yes
mtu: 1460
mru: 1460
authentication: mschap2,mschap1
keepalive-timeout: 30
default-profile: default
[admin@MikroTik] interface pptp-server server>