[Samba] How do I properly format an MX Record?

[Zombie Ryushu]

masterz at olympia:~> sudo samba-tool dns add olympia pukey olympia MX 100 
10 olympia
Usage: samba-tool dns add <server> <zone> <name> 
<A|AAAA|PTR|CNAME|NS|MX|SRV|TXT> <data>