Zoho smtp being blocked

Zoho smtp being blocked

Not sure if this is the right Forum but maybe a moderator can redirect.  Just had some of my emailed invoices get bounced.  Turns out one of SPAM Assassin's Blacklist providers has blocked the smtp ip for Zoho - 72.5.230.67.  Check it here: http://www.uceprotect.net/en/rblcheck.php. ; So I have to export to pdf and email separately, but it's not as convenient as the original Zoho service.  Anyone else experiencing this?