On Thu, Apr 03, 2014 at 02:00:36PM -0500, d...@powerstandards.com wrote: > What I'd like to do is check on a postfix start or reload that these few > addresses are reachable *before* I do things like set up firewalls, etc., > then stop sending out probes at all. Basically, I want to ping the email > address and notify admins (via some channel) that an email address > reachable or not.
/usr/sbin/sendmail -f bounce-address -bv probe-address Will trigger a connection to the nexthop relay of the probe address and an incomplete mail transaction (through "RCPT TO"). The results will be returned to bounce-address (if not empty), and recorded in the mail log. -- Viktor.