[afnog] Problems Sending Mail to Yahoo

[Dr Paulos Nyirenda]

All,

We raised this Yahoo error issue on this AFNOG list a few months ago in January 2008 as
you can see below. Maybe you can benefit from the then discussion and responses in the
archive as well. Following that we noted that Yahoo put more text explanation in their
error messages and performance in Yahoo mail delivery improved for a while but it has
deteriorated again of late.

Our understanding is that this problem is at Yahoo and they need to fix it.

Regards,

Paulos
==============================
Dr Paulos Nyirenda
Malawi SDNP Coodinator


------- Forwarded message follows -------
Date sent:      	Fri, 11 Jan 2008 13:01:52 -0800
To:             	AFNOG <afnog at afnog.org>
From:           	SM <sm at resistor.net>
Subject:        	Re: [afnog] [Fwd: (Fwd) yahoo err - Re: Postfix error not
 	sending mail to outsid]
Copies to:      	Dr Paulos Nyirenda <paulos at sdnp.org.mw>
Keywords:       	

At 10:49 11-01-2008, Paulos Nyirenda wrote:
>We have seen similar errors with Yahoo! as I indicate below and show
>what action we have taken. For example this log entry seems to show
>that Yahoo! is turning down your connection
>
>>     Jan9 13:34:50 mail postfix/smtp[10337]: C2F1336254D:
>>     to=<mywarra at yahoo.com>,
>>     relay=d.mx.mail.yahoo.com[216.39.53.2]:25, delay=3.4,
>>     delays=0.07/0/3.4/0, dsn=4.4.2, status=deferred (lost
>>     connection with d.mx.mail.yahoo.com[216.39.53.2] while
>>     receiving the initial server greeting)

The d.mx.mail.yahoo.com server is not turning down the 
connection.  The above entry indicates a network connectivity issue.

>On some of the mail servers that we administer, we have also recently
>
>encountered errors of the form:
>
>>... while talking to d.mx.mail.yahoo.com.: <<< 421 Message from 
>>(w.x.y.z) temporarily deferred - 4.16.50. Please refer to 
>>http://help.yahoo.com/help/us/mail/defer/defer-06.html

This is a different type of error.  In the above case, the 
d.mx.mail.yahoo.com gives a temporary error, then closes the SMTP connection.

>where w.x.y.z is a mailserver IP that we administer. Exhaustive
>checking on whether the mailserver IP is blacklisted shows that it is
>
>NOT blacklisted. The only service showing these bounces is Yahoo! and

Even if the mail server IP address is not listed in the usual 
blacklists (DNSRBLs), it does not mean that it isn't blacklisted by 
some providers.

>unfortunately NOT every message through w.x.y.z bounces.
>
>Our conclusion is that this problem is at Yahoo! When contacted Yahoo
>
>claims that these errors are not permanently fatal and that we should
>
>keep trying to send BUT our mailservers eventaually time many of
>these messages out and bounce them.

The problem is that Yahoo is temporarily rejecting your message.  The 
behaviour from Yahoo's mail servers is different from greylisting 
though.  If the message is not accepted after several retries, it may 
be that Yahoo views the mail server as not complying with their guidelines.

>Does anyone know whether and where Yahoo! keeps their internal
>blacklists?

It seems so.

>Since we see that occassionally some messages get through to other
>Yahoo! addresses even from the w.x.y.z mailserver, could this be
>cuased by individual Yahoo! accounts?

I doubt it.

I suggest reading 
http://www.maawg.org/about/MAAWG_Sender_BCP/MAAWG_Senders_BCP_Combine.pdf 
if you send email to U.S. based ISPs.

Regards,
-sm 

------- End of forwarded message -------


On Thu, 10 Apr 2008 20:00:14 +0300, Peter Nyamukusa wrote
> Hi Guys,
> 
> I am just wondering if any of you are having issues sending email to yahoo
> especially if you are an ISP. I noticed as of yesterday most of the mail to
> yahoo is deferred and little trickles out at a snails pace. It seems a while
> back they implemented some form of Grey-listing in order to help fight spam.
> Any comments/feedback welcome
> 
> Cheers
> Peter
> 
> _______________________________________________
> afnog mailing list
> http://afnog.org/mailman/listinfo/afnog


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