Zoho Email- More than 100 Sent Emails are missing from Sentbox and Inbox

Zoho Email- More than 100 Sent Emails are missing from Sentbox and Inbox

Hello there,
I am using a free account of Zoho Email from Jan'2015.
This is free plan and associated with single domain name.

Today April 2017, i was searching for some sent emails in Sentbox
I saw that all emails before October 2016 was missing from sentbox and Inbox.

I have never deleted a single email , because i keep it safe for future use.
Also i do not use android app, so no excuse of being deleted from mobile.
I have not archived them as well.

Please check and return back by emails as i sent important quotes to my clients,
which is now missing.

If this is not resolved, i will leave the zohomail instantly and also not suggest anybody to use zohomail.
I was thinking of purchasing a premium plan, but this is a serious error.

Contact
Sandeep
director@triwebsol.com