RealSender | dedicated smtp server

RealSender | dedicated smtp server offers an online check tool
 to validate your SPF settings sending an email message:

 1. send an email to
 2. check online the SPF validation results
     (it will take a minute to appear)

 During verification, a prefix is added to the subject
 if the message is not authenticated correctly. promotes the limit
 on the number of recipients per message, to reduce
 the risk of sending cc/bcc to many addresses.
 We share a list of 300 addresses for testing.
 The messages will reach a "black-hole" mailserver.
 You can use them at your convenience
 to check how many recipients per message
 your smtp server allows the sending.