The email address listed in your Account is considered the account owner and this email address is used for all correspondence from the MantisHub team. This includes emails for invoices/statements and system notifications.
To update your contact details, any administrator in MantisHub can make the change by accessing the 'Billing' tab available from the 'Manage' page in your MantisHub.
Go to the 'Billing' tab and select 'My Account' from the top right corner under the account name.
Update the contact details, tick the 'update contact details' for the relevant subscription and then click 'Save'. Note that you can also include multiple contacts by adding details to the cc field.
If you end up changing your account admin email address it won't reflect in the footer of your MantisHub. We will need to contact support to apply the change (requires a paid plan).