Well to be honest there is no sure shot way to ensure this. But you can try to place a question or something that requires them to reply or ask for a suggestion from them. If the reply you receive is something in context to what you shared in your email, you will know that they received your mail and understood it as well.
First of all,you must to convince your members in your results , you give them the personal example that you set the right strategy in the management of your team , so that they could start developing their own team , with your advice, they set an indicative timetable or pattern according to which they able to achieve initial results.
Anyway,let that be a basis for the initial steps of the new members , as well as those who give up in the beginning .
Hello
If you send messages to the right address or the address specified in the registration member then send a message to the right address. If you do not have to answer it possible to PSA or CSA does not want to communicate or do this job, just ignore it. It may be that you do not check your mail box, so I advise you to send messages to the SFI inbox, chat
I think they should be invited to work, give them some advice, and then you see on your gynecology that you are there on the net, if they do, ie to increase their points versa.
Send them regular mail, instructions on how to operate if they are beginners, maybe vividly explain or send a video ..
Sometimes the hard work pays off, sometimes ne..ali mainly to. I hope I have helped a little.