ip Address Currently Being Blocked

ip Address Currently Being Blocked

Hello,

Currently having a problem sending mail from my zoho.com mail account. I get this mailer-daemon message (in blue font):

This message was created automatically by mail delivery software.
A message that you sent could not be delivered to one or more of its recipients. This is a permanent error.

XXXXXXXXXXXXXXXX Invalid Address, ERROR_CODE :550, ERROR_CODE :5.7.0 Blocked - see https://support.proofpoint.com/dnsbl-lookup.cgi?ip=74.201.84.155: XXXXXXXXXXXXXX


Received:from mail.zoho.com by mx.zohomail.com
    with SMTP id XXXXXXXXXXXXXXXXXXXXXX6894; Tue, 28 Apr 2015 15:15:12 -0700 (PDT)


I have been using zoho without problem until now, but I think I know what caused the issue. I was searching in a forum about changing the php on a theme for a wordpress website and I pasted in a snippet of php code, and this tab popped up in my browser : https://www.elegantthemes.com/forum/search.php?keywords=%3C%3Fphp+the_excerpt%28%29%3B+%3F%3E&terms=all&author=&fid[]=62&sc=1&sf=all&sk=t&sd=d&sr=posts&st=0&ch=300&t=0&submit=Search

Is this a blacklisting created by Zoho itself? And if so is it possible to unblacklist me?