I would like to ask if there is a way to check if your emails are also sent to another email. I work for company and i think they are ''tracking'' my email adress and want to check if this is true. I think that when someone send me email, one copy goes to me and another to my boss. Is there a way to check this?
TL;DR: Yes, your email is probably being monitored. No, it's neither illegal nor unusual for your company to do this. You shouldn't be using work email for egregious non-work uses.
If your email goes through a managed server then there are ways for IT to set up such monitoring processes. They will only be able to monitor your work email address, personal email addresses, so long as they are from an independent third party (such as gmail, yahoo, your personal ISP, etc) would not have this monitoring.
A normal part of a previous job of mine was to sample employee emails to ensure they were abiding by company security policy. It's understood that when you work for a company, the company resources are used at the company's discretion and according to the company's direction. Your email being monitored is neither unusual nor alarming unless you are engaging in behavior detrimental to your company or to your status as their employee.
If you are using a webmail provider (like Gmail) they likely are not tracking you (you may need to check if there is a SSL proxy, but that is another question) if you use something like outlook or some other program running on your machine it would be very easy for your boss to do what you are concerned about.
There is no way to tell without bribing the head of IT with pizza and beer to find out if this is being done.