Author: Lasse Birnbaum Jensen Date: To: Lasse Birnbaum Jensen CC: exim-users, Paul Subject: Re: [exim] Funny and sad side of grey listing when they have multiple
MX...
Lasse Birnbaum Jensen wrote: > I use the /24 subnet instead of the specific ip address that work were well
>
> It done via mysql calls in exim.conf and work great
>
Forgot to mention, i use the same backend database for all my mx servers
> /Lasse
>
> Paul wrote:
>
>> This is not a problem with exim - but others may notice it in their
>> logs, and since I did not immediately twig to the cause, I thought I'd
>> post it on this list to help others...
>>
>> On a routine trawl through my logs, I noticed one of the sites
>> regularly sent to is now greylisting - so far so good, exim doesn't
>> care and beyond that it uses more of my resources for each message
>> neither do I... but now for the funny bit - initially I thought the
>> exim retry mechanism was broken (it isn't) because there was an
>> (almost) instant retry on the temporary failed delivery... then I
>> worked out why - take a look at this log below (email addresses
>> altered to protect the guilty).
>>
>> 2006-01-28 19:02:06 1F2l24-0000rB-2E <= abc@???
>> H=([203.12.35.101]) [203.12.35.101] P=esmtp S=829
>> id=43DB325B.3050907@???
>>
>> Initial try fails because of grey listing
>> 2006-01-28 19:02:13 1F2l24-0000rB-2E SMTP error from remote mail
>> server after RCPT TO:<abc@???>: host vscan2.hotkey.net.au
>> [202.138.0.45]: 450 <abc@hotke
>> y.net.au>: Recipient address rejected: Policy Rejection: Hotkey
>> Greylisting in progress ... Please try again after 2 minutes
>>
>> A subsequent try, almost immediately - this is what made me think my
>> retry config was wrong
>> 2006-01-28 19:02:19 1F2l24-0000rB-2E SMTP error from remote mail
>> server after RCPT TO:<abc@???>: host vscan3.hotkey.net.au
>> [202.138.0.46]: 450 <abc@hotke
>> y.net.au>: Recipient address rejected: Policy Rejection: Hotkey
>> Greylisting in progress ... Please try again after 2 minutes
>>
>> And another subsequent, try, again, almost immediately
>> 2006-01-28 19:02:20 1F2l24-0000rB-2E == abc@??? R=dnslookup
>> T=remote_smtp defer (-44): SMTP error from remote mail server after
>> RCPT TO:<abc@???
>> u>: host vscan1.hotkey.net.au [202.138.0.44]: 450 <abc@???>:
>> Recipient address rejected: Policy Rejection: Hotkey Greylisting in
>> progress ... Please try again af
>> ter 2 minutes
>>
>> Finally it gets through...
>> 2006-01-28 19:25:19 1F2l24-0000rB-2E => abc@??? R=dnslookup
>> T=remote_smtp H=vscan1.hotkey.net.au [202.138.0.44]
>> 2006-01-28 19:25:19 1F2l24-0000rB-2E Completed
>>
>>
>> Then of course I realised why - the network hotkey.net.au has three MX
>> hosts at 202.138.0.45, 202.138.0.46 and 202.138.0.44.
>>
>> This blew me away - what is the point of providing redundancy and
>> scalability via MX, then those hosts each separately decide not to
>> talk to you because of grey listing.
>>
>> Perhaps people doing grey listing should only have the one MX?
>>
>> I guess this is just another example of why grey listing is anti
>> social - thankfully I'm not paying by data volume (many people in
>> Australia still do) or I'd be more annoyed.
>>
>> I sent a message to the postmaster of the site and he had not realised
>> it worked that way (I was surprised he answered - very rare for anyone
>> to answer a postmaster message these days) - all he has done is
>> whitelist my domain in whatever software he uses - good for me, but
>> still poor for everyone else.
>>
>> Regards
>> Paul
>>
>
>
--
Venlig hilsen / Best regards
Lasse Birnbaum Jensen