Finally I've chosen to use an SMTP account to send email notifications:
Personally I've an Amazone account (You Can use Gmail) :
1) In /home/git/gitlab/config/envirenoments/production.rb comment this line :
#config.action_mailer.delivery_method = :sendmail
2) Add this (with correct credentials) just before end tag :
config.action_mailer.delivery_method = :smtp
config.action_mailer.smtp_settings = {
:address => 'gmail.com', # Or an other SMTP provider
:port => 467, # Port depends on your provider
:domain => 'gitlab.yourserver.com', # Your Gitlab main url
:authentication => :plain,
:user_name => 'your gmail id',
:password => 'yourPassword',
:enable_starttls_auto => true }
Thank you, I hope it gonna help you.