On Mon, 30 Mar 2020 13:11:42 +0200 Bastian Blank <bastian+postfix-users=postfix....@waldi.eu.org> wrote:
> On Mon, Mar 23, 2020 at 01:04:44PM -0500, Ranjan Maitra wrote: > > So, I am wondering if I it is possible to have a setup whereby postfix is > > delayed unless/until VPN is up and running. If VPN is down, then I would > > like postfix to be delayed until such time as it comes up. If it is > > possible, how do I go about doing this? Other ideas? > > I would just reject SMTP connections outgoing on your non-VPN interfaces. > > | iptables -A OUTPUT -o $vpn -m tcp --dport 25 -j ACCEPT > | iptables -A OUTPUT -m tcp --dport 25 -j REJECT > So, I was trying this out: $ sudo iptables -A OUTPUT -o $vpn -m tcp --dport 25 -j ACCEPT Try `iptables -h' or 'iptables --help' for more information. Should I be matching with something other than tcp? Many thanks, Ranjan
