The reply-to address is the e-mail address specified by the e-mail template, but the actual e-mail address in the from address is firstname.lastname@example.org. Will this not look suspicious to the recipient and/or increase the risk of the e-mail being captured by spam-filters?
In short: No, this is the best practice used by all major newsletter campaign solutions and transactional e-mail services. This way of sending e-mails minimize the the risk e-mails being stopped by spam-filters, and is necessary for automatic management of bounces and tracking opens and clicks.
If you want the longer answer it comes here:
E-mails sent via the Mira system are sent via Mandrill. Mandrill is one of the largest email service providers in the world, and the email infrastructure behind MailChimp, one of the leading email newsletter services: They have a network of servers all over the world, see http://mandrill.com/
Due to the nature of how emails are sent over the Internet, it is never possible to guarantee delivery, but Mira Network follow best practices to ensure that all emails are delivered. Also, the mnsvc.com domain is only used by Mira Network clients. And since our clients send e-mails that have a much higher open and click frequency than most email service providers, we have an excellent spam ”reputation”, further increasing the chances that emails are delivered.