Yes, those kind of statistics are planned to be included in the future. However, there are some other features and fixes with higher priority at the moment like mail preview before sending, code cleanup, ability to send mail via WordPress’ built in function etc.
Statistics about the amount of mails opened are pretty difficult to get though, and the methods currently available is not an exact science..
Rejected emails can usually be seen in the inbox of the mail that’s sending the mails. Probably there are some way to get the statistics to the plugin, I will look into it.
Links can be checked if you have your WordPress blog act the same way as an URL shortening service, but without the shortening and with the statistics. Maybe I can integrate some existing free service for this purpose. If anyone know more than me on this subject, please tell.
As with all statistics and collecting user data it’s important to have some sort of privacy policy, maybe I’ll implement some sort of privacy-template to use in the mails.
