All;

I installed sendmail via yum, but if I test it like this:

echo “Subject: sendmail test” | sendmail sbob@quadratum-braccas.com

I get a local mail on the server with this every time:

Message  1:
From MAILER-DAEMON@kdb-bugs.example.com  Sun Apr 19 10:15:00 2020
Return-Path:
Date: Sun, 19 Apr 2020 10:15:00 -0600
From: Mail Delivery Subsystem
To:
Content-Type: multipart/report; report-type=delivery-status;
        boundary=”03JGF0ni013558.1587312900/kdb-bugs.example.com”
Subject: Returned mail: see transcript for details Auto-Submitted: auto-generated (failure)
Status: R

Part 1:

The original message was received at Sun, 19 Apr 2020 10:02:56 -0600
from localhost [127.0.0.1]

   —– The following addresses had permanent fatal errors —–

    (reason: 554 5.7.1 Service unavailable; Client host [50.243.150.81]
blocked using xbl.spamhaus.org.rbl.local; https://www.spamhaus
.org/query/ip/50.243.150.81)

   —– Transcript of session follows —–
… while talking to in1-smtp.messagingengine.com.:
>>> RCPT To:
<<< 554 5.7.1 Service unavailable; Client host [50.243.150.81] blocked using xbl.spamhaus.org.rbl.local; https://www.spamhaus.org/quer y/ip/50.243.150.81 554 5.0.0 Service unavailable >>> DATA
<<< 421 4.4.2 mx5.messagingengine.com Error: timeout exceeded ... while talking to in2-smtp.messagingengine.com.: >>> DATA
<<< 421 4.4.2 wmx2.messagingengine.com Error: timeout exceeded Thanks in advance If it helps, here is my sendmail.mc file: [root@kdb-bugs ~]# cat /etc/mail/sendmail.mc divert(-1)dnl dnl # dnl # This is the sendmail macro config file for m4. If you make changes to dnl # /etc/mail/sendmail.mc, you will need to regenerate the dnl # /etc/mail/sendmail.cf file by confirming that the sendmail-cf package is dnl # installed and then performing a dnl # dnl #     /etc/mail/make dnl # include(`/usr/share/sendmail-cf/m4/cf.m4')dnl VERSIONID(`setup for linux')dnl OSTYPE(`linux')dnl dnl # dnl # Do not advertize sendmail version. dnl # dnl define(`confSMTP_LOGIN_MSG', `$j Sendmail; $b')dnl dnl # dnl # default logging level is 9, you might want to set it higher to dnl # debug the configuration dnl # dnl define(`confLOG_LEVEL', `9')dnl dnl # dnl # Uncomment and edit the following line if your outgoing mail needs to dnl # be sent out through an external mail server: dnl # dnl define(`SMART_HOST', `smtp.your.provider')dnl dnl # define(`confDEF_USER_ID', ``8:12'')dnl dnl define(`confAUTO_REBUILD')dnl define(`confTO_CONNECT', `1m')dnl define(`confTRY_NULL_MX_LIST', `True')dnl define(`confDONT_PROBE_INTERFACES', `True')dnl define(`PROCMAIL_MAILER_PATH', `/usr/bin/procmail')dnl define(`ALIAS_FILE', `/etc/aliases')dnl define(`STATUS_FILE', `/var/log/mail/statistics')dnl define(`UUCP_MAILER_MAX', `2000000')dnl define(`confUSERDB_SPEC', `/etc/mail/userdb.db')dnl define(`confPRIVACY_FLAGS', `authwarnings,novrfy,noexpn,restrictqrun')dnl define(`confAUTH_OPTIONS', `A')dnl dnl # dnl # The following allows relaying if the user authenticates, and disallows dnl # plaintext authentication (PLAIN/LOGIN) on non-TLS links dnl # dnl define(`confAUTH_OPTIONS', `A p')dnl dnl # dnl # PLAIN is the preferred plaintext authentication method and used by dnl # Mozilla Mail and Evolution, though Outlook Express and other MUAs do dnl # use LOGIN. Other mechanisms should be used if the connection is not dnl # guaranteed secure. dnl # Please remember that saslauthd needs to be running for AUTH. dnl # dnl TRUST_AUTH_MECH(`EXTERNAL DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl dnl define(`confAUTH_MECHANISMS', `EXTERNAL GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl dnl # dnl # Rudimentary information on creating certificates for sendmail TLS: dnl #     cd /etc/pki/tls/certs; make sendmail.pem dnl # Complete usage: dnl #     make -C /etc/pki/tls/certs usage dnl # dnl define(`confCACERT_PATH', `/etc/pki/tls/certs')dnl dnl define(`confCACERT', `/etc/pki/tls/certs/ca-bundle.crt')dnl dnl define(`confSERVER_CERT', `/etc/pki/tls/certs/sendmail.pem')dnl dnl define(`confSERVER_KEY', `/etc/pki/tls/certs/sendmail.pem')dnl dnl # dnl # This allows sendmail to use a keyfile that is shared with openLDAP's dnl # slapd, which requires the file to be readble by group ldap dnl # dnl define(`confDONT_BLAME_SENDMAIL', `groupreadablekeyfile')dnl dnl # dnl define(`confTO_QUEUEWARN', `4h')dnl dnl define(`confTO_QUEUERETURN', `5d')dnl dnl define(`confQUEUE_LA', `12')dnl dnl define(`confREFUSE_LA', `18')dnl define(`confTO_IDENT', `0')dnl dnl # If you're operating in a DSCP/RFC-4594 environment with QoS dnl define(`confINET_QOS', `AF11')dnl dnl FEATURE(delay_checks)dnl FEATURE(`no_default_msa', `dnl')dnl FEATURE(`smrsh', `/usr/sbin/smrsh')dnl FEATURE(`mailertable', `hash -o /etc/mail/mailertable.db')dnl FEATURE(`virtusertable', `hash -o /etc/mail/virtusertable.db')dnl FEATURE(redirect)dnl FEATURE(always_add_domain)dnl FEATURE(use_cw_file)dnl FEATURE(use_ct_file)dnl dnl # dnl # The following limits the number of processes sendmail can fork to accept dnl # incoming messages or process its message queues to 20.) sendmail refuses dnl # to accept connections once it has reached its quota of child processes. dnl # dnl define(`confMAX_DAEMON_CHILDREN', `20')dnl dnl # dnl # Limits the number of new connections per second. This caps the overhead dnl # incurred due to forking new sendmail processes. May be useful against dnl # DoS attacks or barrages of spam. (As mentioned below, a per-IP address dnl # limit would be useful but is not available as an option at this writing.) dnl # dnl define(`confCONNECTION_RATE_THROTTLE', `3')dnl dnl # dnl # The -t option will retry delivery if e.g. the user runs over his quota. dnl # FEATURE(local_procmail, `', `procmail -t -Y -a $h -d $u')dnl FEATURE(`access_db', `hash -T -o /etc/mail/access.db’)dnl FEATURE(`blacklist_recipients’)dnl EXPOSED_USER(`root’)dnl dnl #
dnl # For using Cyrus-IMAPd as POP3/IMAP server through LMTP delivery uncomment dnl # the following 2 definitions and activate below in the MAILER
section the dnl # cyrusv2 mailer. dnl #
dnl define(`confLOCAL_MAILER’, `cyrusv2′)dnl dnl define(`CYRUSV2_MAILER_ARGS’, `FILE /var/lib/imap/socket/lmtp’)dnl dnl #
dnl # The following causes sendmail to only listen on the IPv4 loopback address dnl # 127.0.0.1 and not on any other network devices. Remove the loopback dnl # address restriction to accept email from the internet or intranet. dnl #
DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA’)dnl dnl #
dnl # The following causes sendmail to additionally listen to port 587 for dnl # mail from MUAs that authenticate. Roaming users who can’t reach their dnl # preferred sendmail daemon due to port 25 being blocked or redirected find dnl # this useful. dnl #
dnl DAEMON_OPTIONS(`Port=submission, Name=MSA, M=Ea’)dnl dnl #
dnl # The following causes sendmail to additionally listen to port 465, but dnl # starting immediately in TLS mode upon connecting. Port 25 or 587
followed dnl # by STARTTLS is preferred, but roaming clients using Outlook Express can’t dnl # do STARTTLS on ports other than 25. Mozilla Mail can ONLY use STARTTLS
dnl # and doesn’t support the deprecated SMTPs; Evolution <1.1.1 uses SMTPs dnl # when SSL is enabled-- STARTTLS support is available in version 1.1.1. dnl # dnl # For this to work your OpenSSL certificates must be configured. dnl # dnl DAEMON_OPTIONS(`Port=smtps, Name=TLSMTA, M=s')dnl dnl # dnl # The following causes sendmail to additionally listen on the IPv6 loopback dnl # device. Remove the loopback address restriction listen to the network. dnl #
dnl DAEMON_OPTIONS(`port=smtp,Addr=::1, Name=MTA-v6, Family=inet6′)dnl dnl #
dnl # enable both ipv6 and ipv4 in sendmail:
dnl #
dnl DAEMON_OPTIONS(`Name=MTA-v4, Family=inet, Name=MTA-v6, Family=inet6′)
dnl #
dnl # We strongly recommend not accepting unresolvable domains if you want to dnl # protect yourself from spam. However, the laptop and users on computers dnl # that do not have 24×7 DNS do need this. dnl #
FEATURE(`accept_unresolvable_domains’)dnl dnl #
dnl FEATURE(`relay_based_on_MX’)dnl dnl #
dnl # Also accept email sent to “localhost.localdomain” as local email. dnl #
LOCAL_DOMAIN(`localhost.localdomain’)dnl dnl #
dnl # The following example makes mail from this host and any additional dnl # specified domains appear to be sent from mydomain.com dnl #
dnl MASQUERADE_AS(`mydomain.com’)dnl dnl #
dnl # masquerade not just the headers, but the envelope as well dnl #
dnl FEATURE(masquerade_envelope)dnl dnl #
dnl # masquerade not just @mydomainalias.com, but @*.mydomainalias.com as well dnl #
dnl FEATURE(masquerade_entire_domain)dnl dnl #
dnl MASQUERADE_DOMAIN(localhost)dnl dnl MASQUERADE_DOMAIN(localhost.localdomain)dnl dnl MASQUERADE_DOMAIN(mydomainalias.com)dnl dnl MASQUERADE_DOMAIN(mydomain.lan)dnl MAILER(smtp)dnl MAILER(procmail)dnl dnl MAILER(cyrusv2)dnl

—
`When you say “I wrote a program that crashed Windows”, people just stare at you blankly and say “Hey, I got those with the system, *for free*”.’ (By Linus Torvalds)