I don't want to disappoint you but the problem is probably not at VMs end. VM can see that access which you haven't authorised has been gained to your e-mail account using your e-mail address and your password - authenticated access. If they are seeing this even after you have changed your password the conclusion has to be that your computer is infected with malware that is transmitting your new password to the hackers and spammers. Try a scan with the free trial version of malwarebytes (download it only from the official site). See what you get.
Now I am not ruling out that there may be an another issue here but the most probable explanation is the one I have given above.
Superuser 2017/18 Use Kudos to say thanks Mark answer as "helpful" only when the problem is solved Please don't send me private messages unless I ask you to. I do not work for VM. The advice I give is based on my best understanding of VM policy and practice. You rely on it at your own risk.