Hornetsecurity offers its customers to send massmailings over their relays, for as long as the messags do not contain any harmful content or spam. When sending mass mailings, it is mandatory to adhere to the restrictions provided below. If sending newsletters, additional stadandards need to be met as well.


To send any mass mailing, using the relayservers or their whitelabeled counterparts from the onboarding website is mandatory. You will also need to adhere to these connection restrictions:

  • Max. 20 connections every minute, per relay server
  • Per connection: Max. of 10 emails every minute per relay server


Due to possible variation within the Loadbalancing, a maximum of 3,600 emails every minute shouldn’t be exceeded. Furthermore, it should be avoided to only send 1 email per connection.


Hornetsecurity reserves the right to reduce the right temporarily reduce the sending limits, if other customers are affected by the mass mailing. In addition, if any threat or spam has been identified, the data connection might be blocked without notification.