I have a paid lite mail account with 6 users. Some of the users want to use other clients (e.g., GMail). I know there are several ways to set this up. What I have done is to forward everything to their gmail and now I'm trying to put their GMAIL to send as which requires me to plug in the zoho smtp.

No matter what I do, I get an unauthorized error.

smtp.zoho.com 

465/SSL

User name= userid@xxx_domain.com

Pw = my log in password

Google can't authenticate on that.

I have POP/IMAP turned on and everything else I can think might affect this. 

How can I do this?