I've been working on this so much on my team with practise ..so,I should say that this answer would be definitely"Yes".
As most of us knew that SFI looks complicated which inturn is very simple and easy to understand which all new member always took in the wrong ways.
Therefore,our new member might be inactive for a longtime in afraid complicated works that might engage with SFI,so sending out supportive and useful team mail would be a great tools to motivate or help them understand how the business really works..and might come back to business after understanding how SFI business opportunity works from your direct mail ..