Verify fail on android

Hello, I'am having some trouble registering again the zoho account on my Android Phone, I have a galaxy S7. At the beginning I had no problem by registering the email, receiving and sending, but since a couple of days email doesn't work anymore. It says it has verification problem, I have tried with IMAP and POP and none of them works. I have followed many times step by step, and I registered the SFP and DKIM today and verified. Please can you help me to recover my business mail in my phone!!!