Zoho on Kindle fire

I have Zoho set up as POP on my Kindle Fire. I can receive messages but I have been unable to send any though I was able to send in the past with my previous email account.

I have outgoing server as smtp.zoho.com, SSL (two options here if available or always, I have tried both), Port 465.

Any help would be great though of course I have other options for sending mail but it would be handy!

Thank you.

Jamini