initial commit from appmail

app/views/app_mailer/user_invite.text.erb

@@ -0,0 +1,10 @@
+You've been invited to access the <%= @organization.name %> organization on Postal.
+
+To accept this invitation, please click the link below to create an account or login to an existing one.
+
+<%= Postal.host_with_protocol %>/join/<%= @user_invite.uuid %>
+
+Thanks,
+
+<%= Postal.smtp_from_name %>
+<%= Postal.smtp_from_address %>