How can I access location information via rules, to include the City of a node in an email?
The Location module defines tokens for each piece of info (see below from location.tokens.inc)

So based on this, [node:location:city] should work for a single value, or [node:location:city:0] for the first value if there were multiple values.

  $location['name'] = array(
    'name' =&gt; t("Location Name"),
    'description' =&gt; t('Location Name (If there are multiple locations, N is the iteration, starting with 0).'),
    'dynamic' =&gt; TRUE,
  );
  $location['street'] = array(
    'name' =&gt; t("Street"),
    'description' =&gt; t("Street (If there are multiple locations, N is the iteration, starting with 0)."),
    'dynamic' =&gt; TRUE,
  );
  $location['additional'] = array(
    'name' =&gt; t("Additional"),
    'description' =&gt; t("Additional (If there are multiple locations, N is the iteration, starting with 0)."),
    'dynamic' =&gt; TRUE,
  );
  $location['city'] = array(
    'name' =&gt; t("City"),
    'description' =&gt; t("City (If there are multiple locations, N is the iteration, starting with 0)."),
    'dynamic' =&gt; TRUE,
  );
  $location['province'] = array(
    'name' =&gt; t("State/Province"),
    'description' =&gt; t("State/Province (If there are multiple locations, N is the iteration, starting with 0)."),
    'dynamic' =&gt; TRUE,
  );
  $location['province_name'] = array(
    'name' =&gt; t("State/Province Name"),
    'description' =&gt; t("State/Province Name (If there are multiple locations, N is the iteration, starting with 0)."),
    'dynamic' =&gt; TRUE,
  );
  $location['postal_code'] = array(
    'name' =&gt; t("Postal Code"),
    'description' =&gt; t("Postal Code (If there are multiple locations, N is the iteration, starting with 0)."),
    'dynamic' =&gt; TRUE,
  );
  $location['latitude'] = array(
    'name' =&gt; t("Latitude"),
    'description' =&gt; t("Latitude (If there are multiple locations, N is the iteration, starting with 0)."),
    'dynamic' =&gt; TRUE,
  );
  $location['longitude'] = array(
    'name' =&gt; t("Longitude"),
    'description' =&gt; t("Longitude (If there are multiple locations, N is the iteration, starting with 0)."),
    'dynamic' =&gt; TRUE,
  );
  $location['country'] = array(
    'name' =&gt; t("Country"),
    'description' =&gt; t("Country (If there are multiple locations, N is the iteration, starting with 0)."),
    'dynamic' =&gt; TRUE,
  );
  $location['country_name'] = array(
    'name' =&gt; t("Country Name"),
    'description' =&gt; t("Country Name (If there are multiple locations, N is the iteration, starting with 0)."),
    'dynamic' =&gt; TRUE,
  );