This could be quite risky if you are the victim, because by doing so, the hackers can find out lots of personal information about you, your family, financial or career related Well, if you want to do a little investigation to find out if someone hacked your email, you can do that now in Gmail or Yahoo mail.
First login to gmail then select “Settings” from the upper right corner. The settings screen will appear. Select “Forwarding and POP/IMAP” from the settings tabs. The forwarding and POP/IMAP settings tab will appear. If forwarding is not enabled, your screen will look like this. If forwarding is enabled, your screen will have additional information in the forwarding section.
YouMail not only stops fraud and phishing calls from bothering you, but it is also how to stop robocalls from bothering anyone. When YouMail sees an illegal call, it can notify carriers, enterprises, and the authorities – so they can locate, take down, and punish the callers.
Are you asking how to block their email? Given that, you can get some possible hints from the email headers, tho' the headers can be faked. In gmail, you can view the email headers by clicking the down arrow next to "Reply", at the top-right of the message pane, then select "Show original". (see here for...