In your Skype profile, you need to have a primary email address. Skype uses this email address primarily to send you important communications about your Skype account. You can choose to opt out of other Skype email communications regarding special offers, new features, or invitations to take part in marketing research in your Skype profile.
You can also choose to be searchable in Skype by your primary email address or any supplementary email address, unless you opt out of search. If you want to change your primary email address in Skype, you can do that in your Skype profile.