The number-one mistake made by perhaps ten percent of new website owners: They fail to notify their website registrar (Register.com, Network Solutions, GoDaddy, etc.) when they change their email address.
The result is that these unfortunate users fail to receive important account-renewal notices from their registrar (these messages only go to their old, now-defunct email account): worst-case scenario (I’ve seen it happen), the site owner completely loses ownership of their domain name.
This effectively destroys the worth of your present website address — unless perhaps you want to buy your own domain name back (if it’s for sale by its new owner) for a ridiculously large sum.
If you discontinue the use of your primary email address (this is the address where people can reach you most directly, the same email address that you give online when you pay by credit card), be sure to give your site registrar your new email address so that they can contact you (and won’t be spammed out by your email program settings) at very important times; like when the fee for your domain name is up for renewal, or when your credit card on file has lapsed. Both of these events (especially the credit card lapsing problem) are common, and in each case, the site owner risks losing the rights to their own domain name if the owner doesn’t follow up.
For your own sake, always make sure your site registrar has an email address at which they can contact you to notify you if payment needs to be made or if a credit card has expired.