Here's the scenario: I have two users using their own PCs that access the same zoho hosted email ( User@mydomain.com) via their personal gmail accounts (ie seprate gmail accounts). IMAP enabaled in both gmail and Zoho. Outgoing mail server setup in both GMail accounts is Zoho. 

Incoming messages are not a problem, each PC downloads from zoho incoming mail server.

Issue is with Sent Items via gmail. If one PC sends an email via gmail ( User@mydomain.com), it syncs with zoho outgoing mail server and is shown in zoho sent folder. However it doesn't sync with the other PC's gmail sent folder. That is, even though it shows in Zoho sent folder, it doesn't download to the 2nd PC's gmail sent folder. This is the same both ways, ie whichever PC sends the email, the other PC doesn't show it in the sent folder.

Now if an email is sent directly via Zoho webmail, then it does shown in both PC's gmail sent folder.