DNS looks fine:
$ dig mail.lezetho.xyz A +short
46.202.82.136
$ dig mail.lezetho.xyz AAAA +short
2a0f:85c1:842:40::3f
SPF also OK, but I don’t think + is best choice here (either ~ or -):
$ dig mail.lezetho.xyz TXT +short
"v=spf1 ip4:46.202.82.136 ip6:2a0f:85c1:842:40::3f +all"
However 25/tcp not accessible from outside:
$ nc -vz -w10 46.202.82.136 25
nc: connect to 46.202.82.136 port 25 (tcp) timed out: Operation now in progress