I am running an nginx webserver with unicorn_rails running happily in production at the moment but the Actionmailer cannot send when I try to use my gmail account through the proxy.
My gmail is set up as shown in this link: http://guides.rubyonrails.org/action_mailer_basics.html#action-mailer-configuration-for-gmail
SSH, webmin, https and everything else I have open work fine, just not smtp in actionmailer. It is possible something is strange with the interfaces as ping uses lo by default and trying telnet smtp.gmail.com 587 does nothing.