The standard setting when you send something from Mynewsdesk is that the “from’ address is hello@mynewsdesk.com.

You can customize the from address to your own email address eg. press@company.com. Go to the Settings menu and select Email settings.
To set up a custom “from address”, please read the technical instructions on how to configure DNS settings, giving us authorization to use your email address for your Mynewsdesk account.
This is for Professional or Enterprise customers.