Some of mail user from my organization not able to receive email on zoho mail from other websites like shopify.com but other mail user able to receive. Example: abc@website.com not able receive email from Shopify, but def@website.com able to receive email from Shopify. 

The problem starts from 15 May 2023 until now, as from that date the mail user stop receiving any email from other websites (shopify.com, mutasibank.co.id). That mail user supposed to received multiple emails from that websites daily.

I've been contacting zoho mail support via email with no response whatsoever.