Can I retrieve to Zoho Mail the messages I sent from "external" accounts?

Can I retrieve to Zoho Mail the messages I sent from "external" accounts?

I have three external accounts configured in Zoho Mail. I could easily retrieve the messages in my Inbox on those accounts to Zoho, but I don't know how (or if it is possible) to retrieve also the messages I previously have sent through those accounts. I mean, I would like to make Zoho my only "message center". Even better: is there any way to keep both servers (Zoho and "externals") perfectly synchronized (Inbox and Sent)?