understanding open ports with virtualmin

output of iptables -L -n respect my rules and seems correct ,
but when i run on my personal desktop : nmap IP OF MY SERVER ,
result is strange, says my port 21 is open , 445/tcp filtered microsoft-ds , 111 rpcbind open ,587 submission open;

i attached my output iptables and the output of nmap scan

Is it possible the nmap scan says wrong ?!

the the first rules -A INPUT -p tcp -m tcp --tcp-flags ACK ACK -j ACCEPT in default up.rules isn’t essencial right ?! i never use thise rule before

thanks for help,
Jess