On Fri, May 17, 2013 at 05:53:47PM +0000, Viktor Dukhovni wrote: > On Fri, May 17, 2013 at 12:26:13PM -0500, /dev/rob0 wrote: > Wietse: > > > Increasing the greet-wait to 10+ seconds could result in > > > legitimate clients hanging up, so I would not recommend that. > > > > Do we have any testing to validate this? I'm pretty sure I > > recall from a few years back on the old original SPAM-L list > > that some Sendmail people[1] were saying they used greet > > pauses in excess of 30 seconds. > > It creates a lot of needless congestion on legitimate sending > systems even if they don't hang up. > snip > > Much of the damage to the SMTP infrastructure is done by > well-meaning anti-spam measures. Let's not take it too far.
I understand all this and agree. I'm not advocating a 30+ second greet pause. My original goal was to reduce delays. Most of those who manage really busy outbounds will have gone to the trouble of getting listed on DNS whitelists. And for these outbounds, an occasional 10-second greet pause is better than "Service currently unavailable" and PASS NEW. But I think this is all moot, and my quick fix, to stop querying psbl.surriel.com, was the best. The moral of the story being, use DNSBL sites with adequate response times and five nines. It's probably also moot if the postscreen_dnsbl_threshold score is only calculated when in excess thereof in case of DNS timeouts. -- http://rob0.nodns4.us/ -- system administration and consulting Offlist GMX mail is seen only if "/dev/rob0" is in the Subject:
