In Tendenci 4 and soon in Tendenci 5 you will have the option of a lower cost method of email tracking and having all emails come from your site or domain name. Two low cost options that we recommend are Mailgun, http://www.mailgun.com/ and Amazon Simple Email Services, http://aws.amazon.com/ses/.
Tendenci – The Open Source AMS Blog
Community Blog for Open Source AMS Makers