exim4 remote_smtp defer

Hi,

My exim4 is installed as the default MTA in (a vanilla) Debian stable.
However, about 1/4 to 1/3 or my email can't go through.

I asked about the exim4 delivery problem exim4 delivery problem several
times, but the answers have always been that the remote mail server is to
be blamed. Now exim4 decides to fail on yahoo. This is what I get:

== (E-Mail Removed) R=dnslookup T=remote_smtp defer (110): Connection timed out

I think this is high time to look at the exim4 side for delivery problems,
because thousand even tens of thousand people sent email to yahoo every
day, yet my emails to yahoo stays in my mail queue for days until they are
considered undeliverable. It has always seems to me that exim is much more
picky than sendmail when delivering email.

I searched the meaning of this "remote_smtp defer" error, and get "This is
usually a DNS lookup problem. <you system> looks up for the domain name of
the recipient you are sending the mail to in order to verify that the
domain exists."

However, it seems to me it is not merely a DNS lookup problem. I use
"exim4 -d (E-Mail Removed)" to see what happens when I send mail, and
found that DNS has resolved properly:

host_find_bydns yield = HOST_FOUND (2); returned hosts:
mx3.mail.yahoo.com 64.156.215.18 MX=1
mx3.mail.yahoo.com 64.156.215.8 MX=1
mx3.mail.yahoo.com 64.156.215.5 MX=1
mx3.mail.yahoo.com 67.28.113.19 MX=1
mx3.mail.yahoo.com 64.156.215.6 MX=1
mx1.mail.yahoo.com 4.79.181.15 MX=1
mx1.mail.yahoo.com 4.79.181.14 MX=1
mx1.mail.yahoo.com 67.28.113.10 MX=1
mx1.mail.yahoo.com 67.28.113.11 MX=1
mx2.mail.yahoo.com 67.28.114.36 MX=1
mx2.mail.yahoo.com 4.79.181.13 MX=1
mx2.mail.yahoo.com 67.28.114.35 MX=1
mx2.mail.yahoo.com 4.79.181.12 MX=1
mx4.mail.yahoo.com 66.218.86.156 MX=5
mx4.mail.yahoo.com 68.142.202.11 MX=5
mx4.mail.yahoo.com 68.142.202.12 MX=5
set transport remote_smtp
queued for remote_smtp transport: local_part = yh_usr
domain = yahoo.com
errors_to=NULL
domain_data=NULL localpart_data=NULL
routed by dnslookup router
envelope to: (E-Mail Removed)
transport: remote_smtp
host mx3.mail.yahoo.com [64.156.215.18] MX=1
host mx3.mail.yahoo.com [64.156.215.8] MX=1
host mx3.mail.yahoo.com [64.156.215.5] MX=1
host mx3.mail.yahoo.com [67.28.113.19] MX=1
host mx3.mail.yahoo.com [64.156.215.6] MX=1
host mx1.mail.yahoo.com [4.79.181.15] MX=1
host mx1.mail.yahoo.com [4.79.181.14] MX=1
host mx1.mail.yahoo.com [67.28.113.10] MX=1
host mx1.mail.yahoo.com [67.28.113.11] MX=1
host mx2.mail.yahoo.com [67.28.114.36] MX=1
host mx2.mail.yahoo.com [4.79.181.13] MX=1
host mx2.mail.yahoo.com [67.28.114.35] MX=1
host mx2.mail.yahoo.com [4.79.181.12] MX=1
host mx4.mail.yahoo.com [66.218.86.156] MX=5
host mx4.mail.yahoo.com [68.142.202.11] MX=5
host mx4.mail.yahoo.com [68.142.202.12] MX=5

[...]

mx4.mail.yahoo.com [66.218.86.156] status = unusable (expired)

all IP addresses skipped or deferred at least one address

[...]

post-process (E-Mail Removed) (1)
LOG: MAIN
== (E-Mail Removed) R=dnslookup T=remote_smtp defer (110): Connection timed out
>>>>>>>>>>>>>>>> deliveries are done >>>>>>>>>>>>>>>>

The exim -d output is very lengthy and messy. If necessary, I can post all
of them.

Thanks for your help.

--
Tong (remove underscore(s) to reply)
*niX Power Tools Project: http://xpt.sourceforge.net/
- All free contribution & collection

* Tong * <(E-Mail Removed)> écrivait
news(E-Mail Removed) rge.net:

> mx4.mail.yahoo.com [66.218.86.156] status = unusable (expired)
>
> all IP addresses skipped or deferred at least one address

Hum ! You get the IP but your exim4 set tham as "unusable" because of an
"expiration".

May be your DNS doesn't correctly set the DNS cache record time (for the
yahoo.com domain records) and when checkink with the expiration parameter
of the source domain (yahoo.com) it think that the MX records have
expired.

Do you have a DNS server or DNS cache/proxy on your exim server ?

What is you "nameserver" parameter in your /etc/resolv.conf on your
server ?


Try using another DNS server (the one of your provider, or you own).


Hope it may help