On Thu, 2005-02-03 at 21:12, Jeff Kinz wrote: > On Thu, Feb 03, 2005 at 09:03:24PM -0500, Scot L. Harris wrote: > > On Thu, 2005-02-03 at 20:34, Jeff Kinz wrote: > > > > > > It is inadvisable for anyone using email in a professional capacity > > > to use any form of TMDA (whitelisting/greylisting). > > > > Interesting rant. And I agree with most of what you state about TMDA. > > I refuse to respond to such requests. > > > > However don't lump greylisting in with TMDA. > > Point taken. The exact definitions of what constitutes "whitelisting," > TMDA and greylisting have shifted continuously since their recent rise > in popularity. > > But -according to a Google definition lookup - You are right. > Greylisting is not a form of TMDA. Quote: > ############################################################ > > Greylisting > How it Works <snip> Good explanation of how greylisting works. :) > > > This leaves the possible remaining objection centered around exactly > how long the email will possibly be delayed for, and/or the possibility > that some email systems mail never retry. (poor ones ;-) ) > I have seen very little difference between setting a 30 minute or a 2 minute greylisting delay. Other than starting with a 30 minute delay of course. :) Of course the actual delay is controlled by how the sending MTA queues and retries messages. Based on the log files I have looked at most legit MTAs retry a message several times in the first 5 to 10 minutes. MTAs that don't comply with the RFCs should be identified and removed from the Internet. If they don't respond correctly to a temp failure code then they are subject to loosing email in other situations as well. Probably the biggest problem is identifying server farms where a message may be retried from a different IP address. The greylisting implementations I have seen generally start with a list of such servers which are whitelisted and as such are not greylisted on the first transmission. -- Scot L. Harris webid@xxxxxxxxxx Quantity is no substitute for quality, but its the only one we've got.
