Add free mailing list services

diff --git a/blueprint/mailing-list.md b/blueprint/mailing-list.md
index e3fde05229dd7fab2257ce2bbcce07fd4195ec56..88c54131944468629862df079ff4ada3da533957 100644 (file)
--- a/blueprint/mailing-list.md
+++ b/blueprint/mailing-list.md
@@ -7,3 +7,11 @@
 * Create special admin user?
 * Use a dedicated domain
 * AAAA missing from SPF?
+
+## <https://groups.io/>
+
+<https://groups.io/> [is gratis for lists of up to 100 members](https://groups.io/static/pricing).
+
+## [Google Groups](https://support.google.com/groups/answer/46601?hl=en)
+
+Google Groups is gratis.