I have lost access to my primary e-mail.
Unfortunately there is no option to change your e-mail address. However you can establish your new (accessible) e-mail as an alias.
Proceed to your profile here: https://minergate.com/internal/profile and find an ‘Extra e-mail’ block, enter your new e-mail as your alias and click on ‘Save changes’.
Contact MinerGate Support team and ask to verify your new e-mail.
You’ll know that your alias has been verified when you receive a ‘Welcome’ message from MinerGate to your alias e-mail address.
NB: You will still have to use your original e-mail to log into your account.