MTA-sendmail stat=Deferred: Connection refused by X.X.X.X

Groovy Gorilla

Local sendmail can't deliver local mails. The localhost not responding, what else needs to check?

echo "Subject: sendmail test" | sendmail -v root
root... Connecting to [127.0.0.1] via relay...
220 zika.gattaca.net ESMTP Sendmail 8.15.2/8.15.2/Debian-20; Mon, 12 Apr 2021 10:02:30 -0400; (No UCE/UBE) logging access from: ip6-localhost(OK)-ip6-localhost [127.0.0.1]
>>> EHLO zika.gattaca.net
250-zika.gattaca.net Hello ip6-localhost [127.0.0.1], pleased to meet you
250-ENHANCEDSTATUSCODES
250-PIPELINING
250-EXPN
250-VERB
250-8BITMIME
250-SIZE
250-DSN
250-ETRN
250-AUTH GSSAPI DIGEST-MD5 CRAM-MD5
250-DELIVERBY
250 HELP
>>> VERB
250 2.0.0 Verbose mode
>>> MAIL From:<> SIZE=23 AUTH=
250 2.1.0 <>... Sender ok
>>> RCPT To:<>
>>> DATA
250 2.1.5 <>... Recipient ok
354 Enter mail, end with "." on a line by itself
>>> .
050 <>... Connecting to 192.168.1.4. via esmtp...
050 <>... Deferred: Connection refused by 192.168.1.4.
250 2.0.0 13CE2UWq079303 Message accepted for delivery
root... Sent (13CE2UWq079303 Message accepted for delivery)
Closing connection to [127.0.0.1]
>>> QUIT
221 2.0.0 zika.gattaca.net closing connection

/etc/hosts:

127.0.0.1 localhost.localdomain localhost
127.0.1.1 localhost
# The following lines are desirable for IPv6 capable hosts
::1 ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters 192.168.1.4 zika.gattaca.net zika

/etc/mail/sendmail.mc:

dnl DAEMON_OPTIONS(`Family=inet6, Name=MTA-v6, Port=smtp, Addr=::1')dnl
DAEMON_OPTIONS(`Family=inet, Name=MTA-v4, Port=smtp, Addr=127.0.0.1')dnl
dnl DAEMON_OPTIONS(`Family=inet6, Name=MSP-v6, Port=submission, M=Ea, Addr=::1')dnl
DAEMON_OPTIONS(`Family=inet, Name=MSP-v4, Port=submission, M=Ea, Addr=127.0.0.1')dnl

listen:

tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 32911/sendmail: MTA
tcp 0 0 127.0.0.1:587 0.0.0.0:* LISTEN 32911/sendmail: MTA 

Firewall is disabled anyhow allows 25/TCP and 587/TCP traffic

Thanks!

1 Answer

You local (127.0.0.1) accepted email.
It failed to relay/forward it to 192.168.1.4:25.
Details: sendmail -v makes sendmail use VERB command in SMTP session. When accepted it makes sendmail trace also trace "next hop" SMTP session

Most likely

• your sendmail is configured to use 192.168.1.4:25 as relay for local emails
  see lines starting with DH (MAIL_HUB) or DR (LOCAL_RELAY) in /etc/mail/sendmail.cf
• something is botched in recognizing "this host email name"