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Re: Yahoo Mail Filtering

2010-07-20 21:03:05

J.D. Falk wrote:

On Jul 20, 2010, at 8:09 AM, Hector Santos wrote:

It seem so random in what seems to be always accepting a transaction but 
intermittently delivered or not.

Are you talking about the 4xx replies?  If you check the text of the reply, 
there's usually a URL with a bit more information about the reason.  Same with 
5xx, for that matter.


I have not seen temporary rejects. All transactions accepted with 250. However, it has been noted by others that YAHOO does employ greylisting (in some form). But I have not seen the temporary negative reply codes.


If you're saying the mail is just disappearing, it's possible that your users 
have configured their accounts to delete suspected spam instead of putting it 
in the spam folder.

The issue is that its intermittent and not consistent. Send a test, with the recipient on the phone, he gets it. Send another test, i.e, same message with "TEST #2" as subject, it never arrives. Send "Test #3" it may or not arrive, and so on. No pattern.

However, at some point, we tried the reverse, yahoo to non-yahoo, which arrived each time and then we try sending test messages again. For a moment there, it appeared to work, so we presumed there was a YAHOO user based "auto-white listing" to addresses the user sends mail to. I jumped on this theory because we have that feature - local users can build an auto-white list just by sending mail to to their "social/business" network.

But then we try sending "test #4", "test #5" and so on and they done ever arrive or go into any folder.

Absolutely, no pattern, inconsistent "DISCARDING" and delivery of mail.

I really hope someone with the yahoo story can explain it.

I was somewhat watching to see/hear if there was a related to valid DKEY/DKIM Brownie points or something now expected by YAHOO. But all I know so far about that is that is required by BULK mail senders. We are not bulking here. just individual single shot messages.

Very odd.

--
Sincerely

Hector Santos
http://www.santronics.com

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