1 Topic by kadaca

  • kadaca
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Topic: Some ideas for greylisting

==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
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====

Hi!

The greylisting settings seems to be waiting 15 minutes (by default) before accepting a retried delivery.

What happens if GREYLISTING_BLOCK_EXPIRE is changed to 0 and a secondary MX record for domain is added that points to same mail server?

If I'm thinking this right:
1. Email is sent and greylisting blocks it
2. Email is resent immediately to secondary MX (that points to same server as primary MX)
3. As greylisting block expiry is set to 0, server accepts the email
4. User is happy and the email gets delivered without delay

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2 Reply by craig

  • craig
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  • From: Canada
  • Registered: 2013-09-04
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Re: Some ideas for greylisting

Interesting idea, but this completely negates greylisting. Additionally, some spammers will try delivering their spam to an MX with a *higher* priority (i.e., higher number) *first*, so it seems to me your idea wouldn't accomplish anything.


Craig

3 Reply by kadaca

  • kadaca
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Re: Some ideas for greylisting

It wouldn't matter if spammer tries to deliver to higher priority MX, if both records actually points to same server. In any case the first email would be greylisted anyway.

4 Reply by ZhangHuangbin

  • ZhangHuangbin
  • ZhangHuangbin
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  • Registered: 2009-05-06
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Re: Some ideas for greylisting

- If you set GREYLISTING_BLOCK_EXPIRE=0, then it bypasses at 2nd retry directly, why bother involve a second server? big_smile
- Most servers retry by connecting to the previous server, but big ISPs may try different servers in MX, you cannot expect they all have same behaviour.