Real Time Monitoring Tool Cisco(RTMT) and Postfix - linux

Question

I'm trying to configure the Real Time Monitoring Tool (RTMT) from Cisco against the Postfix mail server in Ubuntu. I have already configured the mail server option in RTMT with the IP address of Postfix and created an alert to send email to a particular address in RTMT.
The aim of this is that I want to get an email everytime that the alarm rises.
I'm able to send mails using the mailutils command, but not able to get work the communication between RTMT and Postfix.
Any ideas?
Here is the main.cf file from post fix.
# See /usr/share/postfix/main.cf.dist for a commented, more complete version
# Debian specific: Specifying a file name will cause the first
# line of that file to be used as the name. The Debian default
# is /etc/mailname.
#myorigin = /etc/mailname
smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no
# appending .domain is the MUA's job.
append_dot_mydomain = no
# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h
readme_directory = no
# TLS parameters
smtpd_tls_cert_file = /etc/ssl/certs/ssl-mail.pem
smtpd_tls_key_file = /etc/ssl/private/ssl-mail.key
smtpd_use_tls = yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.
myhostname = nagiosgp3-desktop
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
mydestination = zenossfg3.com, nagiosfg3-desktop, localhost.localdomain, localhost
relayhost =
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
home_mailbox = Maildir/
smtpd_sasl_auth_enable = yes
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/dovecot-auth
smtpd_sasl_authenticated_header = yes
smtpd_sasl_security_options = noanonymous
smtpd_sasl_local_domain = $myhostname
broken_sasl_auth_clients = yes
smtpd_recipient_restrictions = reject_unknown_sender_domain, reject_unknown_recipient_domain, reject_unauth_pipelining, permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
smtpd_sender_restrictions = reject_unknown_sender_domain
mailbox_command = /usr/lib/dovecot/deliver -c /etc/dovecot/conf.d/01-dovecot-postfix.conf -n -m "${EXTENSION}"
smtp_use_tls = yes
smtpd_tls_received_header = yes
smtpd_tls_mandatory_protocols = SSLv3, TLSv1
smtpd_tls_mandatory_ciphers = medium
smtpd_tls_auth_only = yes
tls_random_source = dev:/dev/urandom

Answer 1

With the current Postfix setup, you should be able to send an email to user#nagiosfg3-desktop and read email with an client when logged in as user. But I understand that is not your aim.
You have to setup Postfix as simple satellite thanks to a relayhost and SMTP protocol. You should use your company SMTP server if there is one.
As you mention a gmail destination, you can also use Google SMTP server as relay, thanks to SASL authentication documentation. As Google requires TLS/SSL to connect to its service, this documentation must be used too:
relayhost = [smtp.gmail.com]:587
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_tls_policy_maps = hash:/etc/postfix/tls_policy
In /etc/postfix/sasl_passwd, you will set your gmail account username and password so that Google allows your Postfix to use its service as relay:
[smtp.gmail.com] username#gmail.com:yourpassword
And the file /etc/postfix/tls_policy to contain:
[smtp.gmail.com]:587 encrypt protocols=TLSv1 ciphers=high