Sent emails not being delivered

Sent emails not being delivered

I am using the free Zoho Mail plan for business. My domain is townin.com and I have set up an email sz@townin.com
I have configured everything as shown in the setup process, added SPF records and Domain key verfication.

I am also able to receive emails properly.
The problem is that when I send an email from my zoho account, the sent emails are not being delivered. I have tried sending to Gmail and Yahoo but no email is delivered, neither do I get any error. 

Please help me resolve this issue as soon as possible.