Is email tracking legal? In a word: NO.
However, you can legally track a user who has given you permission to do so. Have you heard about Privacy policy and Terms of Service pages on websites? These pages usually declare that they will use your data to give you features like email tracking, sales analysis, and so on.
So, yes, email tracking is legal if users have given permission or if the platform owner has given a public declaration. Use it at your own risk.
Well, fun apart, there is no risk.
First, let me explain this to you in detail.
In general, there are two types of email on the internet:
- Transactional emails
- Mass emails
Transactional emails are things like passwords, credit card receipts, and confirmations (such as Hillary Clinton's emails), which are very confidential and must not be tracked. A delivery report from an SMTP server that the email is delivered is all that matters here.
Second comes mass email, such as marketing emails, new product launch announcements...