SMTP Zoho Locked door to my VPS

People someone here has passed pro this problem problem? I have my site on my VPS and use Zoho as a mail server. I configured the contact form to send my emails via SNMP and set up the Zoho data as server, however after several errors using nmap just realizing that port 587 is blocked for both the smtp.zoho.com as to smtp. google.com.

tacio@tacioandrade:~$ sudo nmap smtp.zoho.com -Pn -p 587 Starting Nmap 6.40 ( http://nmap.org ) at 2015-06-26 18:09 BRT Nmap scan report for smtp.zoho.com (74.201.154.90) Host is up. PORT STATE SERVICE 587/tcp filtered submission

Is it the Digital Ocean that is doing this filter or is it the zoho that is barring the ip block of Digital Ocean?

Also follow my iptables -L to show that there is no output block rules on my server:

tacio@tacioandrade:~$ sudo iptables -L Chain INPUT (policy ACCEPT) target prot opt source destination
fail2ban-ssh tcp – anywhere anywhere multiport dports ssh

Chain FORWARD (policy ACCEPT) target prot opt source destination

Chain OUTPUT (policy ACCEPT) target prot opt source destination

Chain fail2ban-ssh (1 references) target prot opt source destination
RETURN all – anywhere anywhere

Thank you in advance any help.