A community mailing list may be available, depending on the community itself. Many websites, including forums, blogs and other dynamic sites, include a community mailing list. Most neighborhoods and other communities also have a mailing list.
If a website has a community mailing list, the home page usually has a prominent button that links to a form, which can be filled out to add an email address to the mailing list.
If a community has a homeowner association, it most likely has a community mailing list. In most cases, this can be obtained by contacting the association's president.
Services such as DirectMail.com offer community mailing lists to businesses wishing to advertise to specific communities or a specific target audience within a community.