1. Create a constituent export.
2. On the Output tab, select Address> Preferred Address> Phones> Phone number.
3. Select the number of phone numbers/e-mails to export, and select the appropriate phone type to use.

Note: This is not available in versions 7.94 and up.  To Export e-mail addresses based on Primary E-mails, export the Phone Number field based on the Is Primary? option for the Order By field.