Originally Posted by Cottsay
Hello! Can you give a little more information, please, such as which distribution you're using, which mail program you're using (most commonly sendmail or postfix) and maybe an excerpt from your mail log. I, personally, have seen "service unavailable" responses being sent from my server when it determines that the incoming transmission is from a "spam" server, as well as for the "host unknown" response. Pretty sure number 4 is not your fault
Hey thanks for reply,
i usually get 3-5% mails in queue and 2-3% mails in bounce
i am using CentOS 5.2 dist and sendmail for mailing....
Sep 2 04:05:27 linux sendmail: n82MVOru027500: to=<email@example.com>, delay=00:04:02, xdelay=00:04:02, mailer=esmtp, pri=144078, relay=mail1.xyz.net. [ip.ip.ip.ip], dsn=4.0.0, stat=Deferred: Connection timed out with mail1.xyz.net.
Sep 2 04:05:28 linux sendmail: n82MNR7E026507: to=<firstname.lastname@example.org>, delay=00:12:01, xdelay=00:12:01, mailer=esmtp, pri=143051, relay=def-com-bk.mr.ddd.com. [18.104.22.168], dsn=4.0.0, stat=Deferred: Connection timed out with def-com-bk.mr.ddd.com.