"Somtimes even to who the mail had been forwarded", hier die Leistungsbeschreibung, leider nur in englischer Sprache :
We offer two packages (www.MailTracking.com/payment.asp) - our Basic plan is only $24 and has almost all the features you have been using. You can find out:-
When your email is opened & read.
How long your email gets read for.
If your email was forwarded and sometimes who it was forwarded to.
Full tracking history (how many times was it re-opened, what was it opened with, how long for, etc - for the recipient as well as the people with forwarded copies.).
Certified Proof of posting - irrefutable digitally signed certificates which you can use to prove that you sent what you did, and exactly when.
Certified Proof of email rendering (ie the email was shown) - digitally signed read-notifications that prove exactly when your email was opened.
DSN enabling, lets you know that your email was delivered properly, right after you click "send".
MDN enabling, prompts your recipient to manually acknowledge that they read your email.
Live, self-updating read-notifications via email which automatically integrate into your existing email program, and instant ICQ read-notifications to tell you the instant your email is first opened.
Your own "Tracked Email Inbox" page on our website holding complete tracking history of your emails for you to refer to at any time.
Link tracking - find out whether or not your recipient clicked on that web page URL you sent to them.
Microsoft Document tracking - find out when/where your Word, Excel, Powerpoint and other documents get opened, and whether they were given to someone else.
Or you may prefer our Premium Plan which is $36 for a whole year, with all the features MailTracking.com offers, including everything in the Basic plan, plus additionally:-
Approximate recipient location (by closest city)
Recipient email software or browser software, Language(s) and software capabilities are reported.
May be possible to receive instant Read-Notifications by Pager or SMS on your cell phone.
Self-Destructing emails provide good protection for your email, helping prevent it from being forwarded, printed, copied or saved anywhere.
Ensured-Receipt emails prevent any possibility of your email being opened without you receiving a Read-Notification, in an unobtrusive and compatible reader format.
Retractable email (coming soon) - You can delete (or change!) Ensured-Receipt and Self-Destructing emails after you have sent them, both before, or even after, your reader has opened it.