If you start receiving these INFO messages, then you either
A) Have Outbound Safe Mode enabled (in which case expect to receive one email per hour reminding you of this fact)
B) Have Zombie and Spyware Protection enabled and you experienced an event which tripped the OSM feature, which locks down emails leaving the organization to prevent your mail server from contributing to a virus or spam outbreak. Expect to receive one email per hour until you login and turn it off.
All of these features are located under Anti-Virus Techniques / Outbound tab. Be careful with these options and take into account all internal email addresses used to send Bulk Email. See this post for a little more on that subject.