In order to transfer all of your email address subscriptions onto a single email address, you will need to first log in with one of the addresses which you no longer want to receive promos to. Just go to your Recipient Dashboard and follow the instructions on screen to log in.
Once in, visit your profile page by clicking on the menu in the top right corner and then on 'My Profile'. Just under your current email address is a link to change your email address. Click on this and type the address you want all of your promos to go to.
Once verified, your email address will automatically update in the mailing lists of all the labels/PR companies which were using the old address. Furthermore, if anyone tries to add your old address to their list then it will automatically be updated to your new one.
Please be aware that this process is irreversible, so make sure you do it the right way round (logging in with the address you don’t want to receive promos to).