Excuse me for my bad english.

We are testing Zoho mail, configure and send an email to a client receive an email with the following error:

Invalid Address, ERROR_CODE: 550, ERROR_CODE: Policy Server Restriction: sender163-mail.zoho.com is blacklisted (spam).

We investigate and we realized the SPF have not changed, but the changes did continue to receive the error message.

What is the SFP?

spf1 v = mx include: ~ all zoho.com

or

v = spf1 include: ~ all zcsend.net

Thank you.