It might be worth checking if the server IP is blacklisted at http://mxtoolbox.com/blacklists.asp
If it is then you can usually submit your IP to the respective blacklists for removal.
If that's not the probelm then I echo what gfgrisales. I have also heard some Digital Ocean regions block email by default (or at least they used to).
If it is then you can usually submit your IP to the respective blacklists for removal.
If that's not the probelm then I echo what gfgrisales. I have also heard some Digital Ocean regions block email by default (or at least they used to).
Before posting, update your profile with your OS, Sentora version and server type!