Problem with mails, senting or receiveing

Problem with mails, senting or receiveing

I am new to Zoho service. I already installed the account and I set the MX records in my server provider Digital Ocean. 

I will describe my issue. I can receice an email to my Hotmail account but I cannot receive an email at  info@dicha.gr
Why this may happens??

Also, I cannot receive any email although  http://mxtoolbox.com/ give me correct results. Please advice what I have to do to fix these issues!