connect to smtp.gmail: Connection refused

I am trying to send mail via Ubuntu 14.04 version to my gmail ID. Ubuntu is running via VMware on my Windows machine. Please let me know if the above description is not clear as I am newbie in working with virtual machine. I haved first installed VMware Workstation 12 Player. Then downloaded ubuntu-14.04.4-desktop-amd64.iso and created a virtual machine for it.

I am trying to run the below command: echo "This is the body of the email" | mail -s "This is the subject line" myemailID

There is no error prompt. I have already executed the following utilities on Ubuntu:

sudo apt-get install mailutils
sudo apt-get install postfix mailutils libsasl2-2 ca-certificates libsasl2-modules
sudo dpkg-reconfigure postfix

I have selected 'Internet site' as mail configuration and rest settings as default. I have checked mail.log file by executing 'tail -f /var/log/mail.log' and following is the message:

Mar 22 16:34:00 ubuntu postfix/qmgr[2743]: 257891057F0: from=<>, size=474, nrcpt=1 (queue active)
Mar 22 16:34:00 ubuntu postfix/smtp[2755]: connect to smtp.gmail.com[74.125.70.109]:587: Connection refused
Mar 22 16:34:00 ubuntu postfix/smtp[2755]: connect to smtp.gmail.com[74.125.70.108]:587: Connection refused
Mar 22 16:34:00 ubuntu postfix/smtp[2755]: 257891057F0: to=<myemailid>, relay=none, delay=0.07, delays=0/0/0.06/0, dsn=4.4.1, status=deferred (connect to smtp.gmail.com[74.125.70.108]:587: Connection refused)
Mar 22 16:34:00 ubuntu postfix/pickup[2744]: 3DE6F10580A: uid=1000 from=<>
Mar 22 16:34:00 ubuntu postfix/cleanup[2753]: 3DE6F10580A: message-id=<20160322110400.3DE6F10580A@ubuntu>
Mar 22 16:34:00 ubuntu postfix/qmgr[2743]: 3DE6F10580A: from=<>, size=476, nrcpt=1 (queue active)
Mar 22 16:34:00 ubuntu postfix/smtp[2755]: connect to smtp.gmail.com[74.125.70.108]:587: Connection refused
Mar 22 16:34:00 ubuntu postfix/smtp[2755]: connect to smtp.gmail.com[74.125.70.109]:587: Connection refused
Mar 22 16:34:00 ubuntu postfix/smtp[2755]: 3DE6F10580A: to=<myemailid>, relay=none, delay=0.05, delays=0/0/0.05/0, dsn=4.4.1, status=deferred (connect to smtp.gmail.com[74.125.70.109]:587: Connection refused)

Please guide and let me know if any other information is required.

/etc/postfix/main.cf file is also mentioned below for reference.

smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no

append_dot_mydomain = no

readme_directory = no


smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.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

smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
myhostname = ubuntu
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
mydestination = ubuntu, localhost.localdomain, localhost
relayhost = [smtp.gmail.com]:587
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options = noanonymous
smtp_tls_CAfile = /etc/postfix/cacert.pem
smtp_use_tls = yes
smtp_tls_policy_maps = hash:/etc/postfix/tls_policy
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
inet_protocols = ipv4
mynetworks = 127.0.0.0/8
mailbox_command = procmail -a "$EXTENSION"

I have emulated firewall issue

# host smtp.gmail.com
smtp.gmail.com is an alias for gmail-smtp-msa.l.google.com.
gmail-smtp-msa.l.google.com has address 74.125.136.109
gmail-smtp-msa.l.google.com has address 74.125.136.108
gmail-smtp-msa.l.google.com has IPv6 address 2a00:1450:4013:c01::6d

# iptables -I OUTPUT -d 74.125.136.108 -j DROP
# iptables -I OUTPUT -d 74.125.136.109 -j DROP

Check connection

# openssl s_client -connect smtp.gmail.com:587 -starttls smtp
socket: Network is unreachable
connect:errno=101

these lines mean that someone on you network is blocking connection to smtp.gmail.com on port 587. You can try another smtp server: smtp-mail.outlook.com:25, smtp.mail.yahoo.com:587, smtp.mail.ru:2525

# openssl s_client -connect smtp.mail.yahoo.com:587 -starttls smtp
CONNECTED(00000003)
depth=3 C = US, O = "VeriSign, Inc.", OU = Class 3 Public Primary Certification Authority
verify return:1
depth=2 C = US, O = "VeriSign, Inc.", OU = VeriSign Trust Network, OU = "(c) 2006 VeriSign, Inc. - For authorized use only", CN = VeriSign Class 3 Public Primary Certification Authority - G5
verify return:1
depth=1 C = US, O = Symantec Corporation, OU = Symantec Trust Network, CN = Symantec Class 3 Secure Server CA - G4
verify return:1
depth=0 C = US, ST = California, L = Sunnyvale, O = Yahoo Inc., OU = Information Technology, CN = smtp.mail.yahoo.com
verify return:1
...
---
250 STARTTLS
quit
221 2.0.0 Bye
closed

P.S. by the way, have you tried port 465?

# openssl s_client -connect smtp.gmail.com:465