On 1/29/2010 11:57 AM, Dan Lists wrote:
When a user mistypes an email address domain (eg @monsant.com), the
message is sitting in the queue for days before they know about it.
We'd like to give them immediate feedback instead of making them wail.
I'm trying to have the outbound mail server permanently reject email
with an invalid sender domain.
I am using postfix 2.7-20100117 on FreeBSD 7.1 p10.
I have:
smtpd_recipient_restrictions =
reject_non_fqdn_recipient,
reject_unknown_recipient_domain,
permit_mynetworks,
reject_unauth_destination
unknown_address_reject_code = 550
This works if the domain exists but the hostname does not, for example
email to nob...@asdf.gmail.com:
Jan 29 11:49:27 outbound postfix/smtpd[65568]: NOQUEUE: reject: RCPT
from hostname[12.34.56.78]: 550 5.1.2<nob...@asdf.gmail.com>:
Recipient address rejected: Domain not found; from=<d...@nowhere.com>
to=<nob...@asdf.gmail.com> proto=ESMTP helo=<hostname>
If the domain does not exist, it is giving a 450. Here is the log for
an email to monsant.com:
Jan 29 11:48:23 outbound postfix/smtpd[65568]: NOQUEUE: reject: RCPT
from hostname[12.34.56.78]: 450 4.1.2<nob...@monsant.com>: Recipient
address rejected: Domain not found; from=<d...@dan@nowhere.com>
to=<nob...@monsant.com> proto=ESMTP helo=<hostname>
How can I make postfix issue a 550 error when the domain does not exist?
Thanks,
Dan
$ host monsant.com
Host monsant.com not found: 2(SERVFAIL)
This is a temporary error. The name server for monsant.com
could not be contacted. You don't know if the domain exists
or not. "whois" shows this domain does exist, but the listed
name servers return an error rather than an authoritative
NXDOMAIN.
$ host asdf.gmail.com
Host asdf.gmail.com not found: 3(NXDOMAIN)
This domain does not exist.
Postfix will always respond with a 450 defer when it can't
find out if a domain exists or not.
Don't confuse temporary errors (you don't know if the domain
exists or not) with permanent errors (domain definitely does
not exist).
If you want to help out fat-fingered users, you can add
frequently misspelled domains to your transport table.
Note: these domains exist, but they don't respond to email.
hotmial.com error:5.1.2 hotmail.com not hotmial.com
hotmai.com error:5.1.2 hotmail.com not hotmai.com
cherter.net error:5.1.2 try "charter.net" instead
monsant.com error:5.1.2 monsanto.com not monsant.com
Changing postfix behavior to immediately return mail on
temporary errors would be a mistake.
-- Noel Jones
