error dmarc dns smtp

hy we have a domain with zoho mail configuration

and when check domain (http://mxtoolbox.com/domain/iilex.com.br/)
show this errors:

- dmarc iilex.com.br Missing or Invalid Record
- dns iilex.com.br SOA Serial Number Format is Invalid
- dns iilex.com.br SOA Expire Value out of recommended range
- smtp mx2.zohomail.com Reverse DNS does not match SMTP Banner

Can someone help?

Thanks.