sendmail and Nagios Core Alerting

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spatchE
Posts: 24
Joined: Tue Oct 30, 2018 8:05 pm

sendmail and Nagios Core Alerting

Post by spatchE »

I have set up Nagios Core successfully and currently monitoring 2 servers.I have also set up my contacts.cfg file with the correct email, and then plugged this contact into the Host and Service windows.cfg file. I know I am missing something in a sendmail config file somewhere in order to point my Office 365 relay to it. (smtp.office365.com Port 587). My commands.cfg file is using the /usr/sbin/sendmail directive to send the email.
Do I update the /etc/mail/sendmail.mc config file for this to point to correct place? If so what and where?
spatchE
Posts: 24
Joined: Tue Oct 30, 2018 8:05 pm

Re: sendmail and Nagios Core Alerting

Post by spatchE »

Do I need to create a symbolic link between the two?
User avatar
tgriep
Madmin
Posts: 9177
Joined: Thu Oct 30, 2014 9:02 am

Re: sendmail and Nagios Core Alerting

Post by tgriep »

I found a few links that describe how to setup sendmail to forward emails to a relay server. Take a look at then for details on how to set up your server's sendmail daemon.

https://tecadmin.net/sendmail-to-relay- ... mail-stmp/
https://www.howtoforge.com/configuring- ... om-address

For the most part, you do need to update the sendmail.mc file and create the auth file.
Be sure to check out our Knowledgebase for helpful articles and solutions!
spatchE
Posts: 24
Joined: Tue Oct 30, 2018 8:05 pm

Re: sendmail and Nagios Core Alerting

Post by spatchE »

This is what I am seeing in the log after following this link:

https://pepipost.com/tutorials/install- ... -centos-7/

Dec 16 20:53:53 nagios sendmail[2519]: daemon MTA: problem creating SMTP socket
Dec 16 20:53:58 nagios sendmail[2519]: NOQUEUE: SYSERR(root): opendaemonsocket: daemon MTA: cannot bind: Address already in use
Dec 16 20:53:58 nagios sendmail[2519]: daemon MTA: problem creating SMTP socket
spatchE
Posts: 24
Joined: Tue Oct 30, 2018 8:05 pm

Re: sendmail and Nagios Core Alerting

Post by spatchE »

From googling this error I see results stating that something else is already listening on the SMTP port. I am needing to use port 587 however and not 25, this is the results I am getting: 192.168.1.5 is my internal IP address of my nagios server, I am trying to send my mail to smtp.gmail.com

[root@nagios log]# sudo netstat -lntup
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 192.168.1.5:25 0.0.0.0:* LISTEN 3338/sendmail: acce
tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 1520/mysqld
tcp 0 0 0.0.0.0:587 0.0.0.0:* LISTEN 3338/sendmail: acce
tcp 0 0 0.0.0.0:465 0.0.0.0:* LISTEN 3338/sendmail: acce
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 1181/sshd


When I stop the sendmail service, and try to connect to port 587 or 25 the connection refuses, but when I start the sendmail service it connects.. so it does not appear there is something else in the way of connecting?
spatchE
Posts: 24
Joined: Tue Oct 30, 2018 8:05 pm

Re: sendmail and Nagios Core Alerting

Post by spatchE »

If I test email through telnet 587 I get the following:

[root@nagios log]# telnet localhost 587
Trying ::1...
telnet: connect to address ::1: Connection refused
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
220 nagios.apifw.com ESMTP Sendmail 8.14.7/8.14.7; Mon, 16 Dec 2019 22:02:06 -0600
HELO testing
250 nagios.apifw.com Hello localhost [127.0.0.1], pleased to meet you
MAIL FROM: spatchephunk@gmail.com
530 5.7.0 Authentication required
User avatar
tgriep
Madmin
Posts: 9177
Joined: Thu Oct 30, 2014 9:02 am

Re: sendmail and Nagios Core Alerting

Post by tgriep »

The message
"530 5.7.0 Authentication required"
Means that Sendmail wants an authentication account to use it for relaying so that will have to be resolved.
Take a look at the website you used to setup Sendmail and verify that the settings are correct.
You may need to add your FQDN of the server or the IP address to the /etc/mail/access file and recompile the Sendmail configuration.
Be sure to check out our Knowledgebase for helpful articles and solutions!
spatchE
Posts: 24
Joined: Tue Oct 30, 2018 8:05 pm

Re: sendmail and Nagios Core Alerting

Post by spatchE »

I did what you said but getting same error, here is my sendmail.cf file:

Code: Select all

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 #
define(`SMART_HOST', `smtp.gmail.com')dnl
define(`RELAY_MAILER_ARGS', `TCP $h 587')dnl
define(`RELAY_MAILER',`esmtp')dnl
define(`ESMTP_MAILER_ARGS', `TCP $h 587')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 #
TRUST_AUTH_MECH(`EXTERNAL DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl
define(`confAUTH_MECHANISMS', `EXTERNAL GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl
FEATURE(`authinfo', `hash /etc/mail/auth/client-info.db')dnl
FEATURE(`access_db', `hash -T<TMPF> -o /etc/mail/access.db')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<TMPF> -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, 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 #
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 #
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 24x7 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(`nagios.apifw.com')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(`apifw.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 #
MASQUERADE_DOMAIN(localhost)dnl
MASQUERADE_DOMAIN(nagios.apifw.com)dnl
dnl MASQUERADE_DOMAIN(mydomainalias.com)dnl
dnl MASQUERADE_DOMAIN(mydomain.lan)dnl
MAILER(smtp)dnl
MAILER(procmail)dnl
dnl MAILER(cyrusv2)dnl

***********Here is my access file ******************'

Code: Select all

# Check the /usr/share/doc/sendmail/README.cf file for a description
# of the format of this file. (search for access_db in that file)
# The /usr/share/doc/sendmail/README.cf is part of the sendmail-doc
# package.
#
# If you want to use AuthInfo with "M:PLAIN LOGIN", make sure to have the 
# cyrus-sasl-plain package installed.
#
# By default we allow relaying from localhost...
Connect:localhost.localdomain		RELAY
Connect:localhost			RELAY
Connect:127.0.0.1			RELAY
Connect:smtp.gmail.com                  RELAY
Connect:192.168.1.5                     RELAY
Connect:nagios.apifw.com                RELAY
*** HERE is my auth file ********* ( I put in blanks for security reasons

Code: Select all

AuthInfo:gmail.com "U:myemail@gmail.com" "P:mypasswordhere" "M:PLAIN"
AuthInfo: "U:myemail@gmail.com" "P:mypasswordhere" "M:PLAIN"
Last edited by tgriep on Tue Dec 17, 2019 3:26 pm, edited 1 time in total.
Reason: Added Code Wraps around large output.
User avatar
tgriep
Madmin
Posts: 9177
Joined: Thu Oct 30, 2014 9:02 am

Re: sendmail and Nagios Core Alerting

Post by tgriep »

I want to be clear is that all you want to do is to receive emails from the Nagios Notification commands and just forward them to smtp.mail.com, is that correct?

Replace the sendmail.mc file with the following. Rebuild the sendmail.cf and restart sendmail.

Code: Select all

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
define(`SMART_HOST', `smtp.gmail.com')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 #
TRUST_AUTH_MECH(`EXTERNAL DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl
define(`confAUTH_MECHANISMS', `EXTERNAL GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl
FEATURE(`authinfo', `hash /etc/mail/auth/client-info.db')dnl
FEATURE(`access_db', `hash -T<TMPF> -o /etc/mail/access.db')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<TMPF> -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 24x7 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

MASQUERADE_AS(`nagios.apifw.com')dnl
FEATURE(masquerade_envelope)dnl
FEATURE(masquerade_entire_domain)dnl
MASQUERADE_DOMAIN(nagios.com)dnl
MAILER(smtp)dnl
MAILER(procmail)dnl
dnl MAILER(cyrusv2)dnl

Send a test email using port 25 to see if sendmail accepts it and then forwards it to smtp.gmail.com.
Check the /var/log/maillog file for any errors.
Be sure to check out our Knowledgebase for helpful articles and solutions!
spatchE
Posts: 24
Joined: Tue Oct 30, 2018 8:05 pm

Re: sendmail and Nagios Core Alerting

Post by spatchE »

All I am trying to do is receive notifications from Nagios that a server is in warning or critical state. I am using my gmail address as the email to send from nagios until I can get my Office 365 set up.

I just did a telnet localhost 25 test and it said it successfully sent an email...but I never got the email....ALSO when I try 587 now the connection refuses:

[root@nagios mail]# telnet localhost 25
Trying ::1...
telnet: connect to address ::1: Connection refused
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
220 nagios.apifw.com ESMTP Sendmail 8.14.7/8.14.7; Tue, 17 Dec 2019 16:37:22 -0600
HELO test
250 nagios.apifw.com Hello localhost [127.0.0.1], pleased to meet you
MAIL FROM: spatchephunk@gmail.com
250 2.1.0 spatchephunk@gmail.com... Sender ok
RCPT TO: it.admin@pelotonland.com
250 2.1.5 it.admin@pelotonland.com... Recipient ok
Subject: Test
500 5.5.1 Command unrecognized: "Subject: Test"
DATA
354 Enter mail, end with "." on a line by itself
Subject: test

this is a test
.
250 2.0.0 xBHMbMEa010306 Message accepted for delivery
QUIT
221 2.0.0 nagios.apifw.com closing connection
Connection closed by foreign host.
[root@nagios mail]# telnet localhost 587
Trying ::1...
telnet: connect to address ::1: Connection refused
Trying 127.0.0.1...
telnet: connect to address 127.0.0.1: Connection refused
[root@nagios mail]#
Locked