Unable to connect SMTP server:smtpout.mail.zoho.com Reason:Authentication failed:554 5.1.8 Sender Address Blocke

Unable to connect SMTP server:smtpout.mail.zoho.com Reason:Authentication failed:554 5.1.8 Sender Address Blocke

Hi. We send automated emails via pop and smtp from a software that we own for customer service. How can I get around these limits? You may email at dodom2@ebscompanyky.com. The account in question is support@linnworkstools.com