Mail not working: [SPAM-SPF] and delivery failed

Mail not working: [SPAM-SPF] and delivery failed

Hi, I'm using Zoho for a long time. After the attack u had I started with these problems. Every mail I send, it goes with this on the header: "[SPAM-SPF]". This is if it the mail is sent, because 90% of the time I receive delivery status failed. Also it takes like 30 min to receive or send this errors. Right now Zoho for me isnt working. Please I need some help with these.
Kind regards