> -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of Chris Scott > Sent: Saturday, August 16, 2003 10:05 AM > To: [EMAIL PROTECTED] > Subject: Re: [IMail Forum] Anyone have any experiences with Postini ? > > > David Sullivan wrote: > > > There are a couple of items I think should be distinguished that may > > affect everyone's point of view. > > <snip some very good comments> > > > > So...I think that's what this whole discussion comes down to...cost > > and benefit. Multiple test rejection is great, but as volumes grow you > > just can't rely on it solely unless your willing to accept the > exponentially increasing costs. > > At some point, you've got to start adding some single failures in. > > Good points, all of them. Many single tests are sufficient for > most people > to reject on regardless of the results of other tests. A few I > can think of:
I compleely agree. In a business setting, single failure filtering is very acceptable and I have had no problems using it with so very few false positives I don't even hardly keep track anymore. A business setting is obviously very different than that of an ISP. In a business, lawyers and CEOs determine what they want coming in and out of the mail servers - period. In an ISP, it's a simple matter of supply and demand. The demand is there, that I am sure of, but you must supply various types of users with a single solution that will best serve them all - and a weighted test may make more sense there. Travis > -RCPT TO: a non-existent user. Self explanatory. > -MAIL FROM: a sender that isn't a syntactically correct > email address > or from an invalid domain. If I can't reach them by > email, why should I > accept theirs? > -HELO as my MTA's IP address/hostname and it isn't my MTA. > My MTA can't > send to itself from outside itself. > > There are probably more I'm missing and some I've omitted since > I'm tired of > typing already today. If I reject on these alone, I'm saving resources > (processor, disk, bandwidth, etc.). Why waste those resources on other > tests when I know these should be an absolute reject? > > There are also some tests I may not want to rely on alone but in > conjunction > with other tests, they allow me to make an accept/reject decision. > > > > > Again, IMHO the best combination is a carefully balanced mix between > > single failure rejection AND weighting. > > > > Very good advice. The issue, just like spam, isn't black and white. > > > -- > Chris Scott > Host Orlando, Inc. > http://www.hostorlando.com/ > > > > To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html > List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ > Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/ > To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
