It is people who do not understand this who make comments about author mailing lists no longer working, and people are getting too much email. (pattyjansen.com)
And quite honestly, in my own author mailing list, I have no way of knowing where those subscribers are based because I don't collect mailing addresses, only emails. (startupindieauthor.com)
You may not have a big and bulky author mailing list, but you can send individual emails to friends and family and (politely) ask them to buy your book and join your mailing list. (draft2digital.com)