This looks like greylisting on AOL's part. You can Google the term and read lots about it; it's a fairly common anti-spam tactic, but the downsides to it are quite major (my opinion from running a hosting org for ~18 years). -- | Jeremy Chadwick jdc@koitsu.org | | UNIX Systems Administrator http://jdc.koitsu.org/ | | Making life hard for others since 1977. PGP 4BD6C0CB | On Fri, Oct 04, 2013 at 10:01:07AM -0400, Joshua Boniface wrote:
Hello everyone:
For the last few days I've been noticing mail queuing on our mail servers with errors like this:
(delivery temporarily suspended: host mailin-03.mx.aol.com[205.188.190.2] refused to talk to me: 421 mtain-df04.r1000.mx.aol.com Service unavailable - try again later)
The errors are transient, as forcing delivery tends to send them through. It's happening on many mail servers so it isn't a DNSBL problem on our end.
Has anyone else noticed this?
Thanks, Joshua Boniface _______________________________________________ Outages mailing list Outages@outages.org https://puck.nether.net/mailman/listinfo/outages