Supervision

Donc la solution est :
1. Configure Postfix main configuration

a.vi /etc/postfix/main.cf

b. Add these lines:

smtp_sasl_security_options = noanonymous
relayhost = [smtp.gmail.com]:587
smtp_use_tls = yes
smtp_tls_CAfile = /etc/postfix/cacert.pem
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl/passwd

c. Save and exit

2. Create /etc/postfix/sasl/passwd

a. Create a directory sasl under /etc/postfix and create a file passwd with contents below:

[smtp.gmail.com]:587 username@gmail.com:password

Save and exit

b. Change permission
#chmod 600 /etc/postfix/sasl/passwd

c. Create lookup table via postmap
#postmap /etc/postfix/sasl/passwd

Issuing that command will create passwd.db

3. Generate your own CA certificate

a. Change directory to /etc/pki/tls/certs

#cd /etc/pki/tls/certs

b.Create a key and test certificate in one file

#make hostname.pem

You will something like

[root@FLT certs]# make hostname.pem
umask 77 ; \
PEM1='/bin/mktemp /tmp/openssl.XXXXXX' ; \
PEM2='/bin/mktemp /tmp/openssl.XXXXXX' ; \
/usr/bin/openssl req -utf8 -newkey rsa:1024 -keyout $PEM1 -nodes -x509 -days 365 -out $PEM2 -set_serial 0 ; \
cat $PEM1 > hostname.pem ; \
echo "" >> hostname.pem ; \
cat $PEM2 >> hostname.pem ; \
rm -f $PEM1 $PEM2
Generating a 1024 bit RSA private key
............................++++++
.....++++++
writing new private key to `/tmp/openssl.z12084?
---
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter `.', the field will be left blank.
---
Country Name (2 letter code) [GB]:
State or Province Name (full name) [Berkshire]:
Locality Name (eg, city) [Newbury]:
Organization Name (eg, company) [My Company Ltd]:
Organizational Unit Name (eg, section) []:
Common Name (eg, your name or your server's hostname) []:
Email Address []:

c. Fill-up the necessary information and copy the file on /etc/postfix as cacert.pem

#cp /etc/pki/tls/certs/hostname.pem /etc/postfix/cacert.pem

4. Restart the postfix service

#service postfix restart

NB : "POUR le test mettez :"

echo "Test mail from postfix" | mail -s "Test Postfix" you@example.com