There are two passwords required for email integration - one is the Zoho password, the other is the email password. Zoho Admins don't have access to Users passwords, nor do I or Zoho. The primary reason is security to prove that someone did something ...
Sometimes an IT department (of the recipient) has an anti-spoofing policy that blocks inbound emails when the email address is perceived to be a spoofed email address (which is how Zoho CRM sends your email with your email address).
If you are trying to integrate your email with Zoho CRM and you use two factor authentication (TFA) on your email, you need to generate an app specific password. This can be done by following these instructions: ...