[Greylist-users] Any benefit to changing the TEMPFAIL message?

Hector Santos hsantos at isdg.net
Thu Jun 19 09:26:54 PDT 2008

Albert E. Whale wrote:
> I have been using (and supporting) the GreyListing software (our own 
> version of course), and was wondering if anyone had found any value with 
> changing the standard TEMPFAIL message?
> The only reason I ask this is because some users, and also some Servers 
> will send an email but never retry.

Then they are not following the RFC x821 requirements.

> While I understand that the users which send a message directly to us 
> will see the TEMPFAIL message, they do not necessary understand that it 
> means to retry it again shortly.

The TEXT part is meaningless.  It is the code 45x that triggers a 
temporary negative response.  451 is an "attempt" to major clients be 
more greylist aware, but it is the 45x response that makes it work in 
general.  Nothing after that number should be relied on to control 
client behavior.

> Additionally, the servers that do not resend (wow is this inane), I just 
> do not know how to kick those servers hard enough.

You can't.  And you shouldn't worry about it.  Its not your problem. And 
in my view, the odds are fairly high these type of servers are more 
'spammer-type' than not.

Thats the whole point behind greylisting.  The BAD will not follow the 
basic rules, the GOOD will.

> Any Suggestions?

The best you can do is if you know these specific servers are GOOD 
people, but unfortunately, have broken SMTP software, and you don't have 
an avenue of contact to get them to fix it or its legacy software and 
the author no where to be found, then your only choice is to white list 
them and not greylist them.

Hector Santos, CTO

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