Unable to receive emails from specific domains

Unable to receive emails from specific domains

Hello,

I have been using Zoho for many months and my mails worked perfectly. 
Of late, I have not been receiving mails from many accounts (worked perfectly in the past) but continue to receive mails from accounts associated with Gmail. I am unable to figure out the cause. Kindly help me resolve this issue.

Thanking you in anticipation.

Regards,
Kirsten