SMTP Gmail account working on gitlab but not on gitlab-ci

Hi,

I configured, in /etc/gitlab/gitlab.rb, the gitlab_rails SMTP configuration.

 gitlab_rails['smtp_enable'] = true
 gitlab_rails['smtp_address'] = "smtp.gmail.com"
 gitlab_rails['smtp_port'] = 587
 gitlab_rails['smtp_user_name'] = "account@gmail.com"
 gitlab_rails['smtp_password'] = "password"
 gitlab_rails['smtp_domain'] = "smtp.gmail.com"
 gitlab_rails['smtp_authentication'] = "login"
 gitlab_rails['smtp_enable_starttls_auto'] = true
 gitlab_rails['smtp_tls'] = false
 gitlab_rails['smtp_openssl_verify_mode'] = 'peer'

It works fine. But when I want it to work for gitlab-ci, I put then same config and I don't receive failed build emails. Here is the configuration :

 gitlab_ci['smtp_enable'] = true
 gitlab_ci['smtp_address'] = "smtp.gmail.com"
 gitlab_ci['smtp_port'] = 587
 gitlab_ci['smtp_user_name'] = "account@gmail.com"
 gitlab_ci['smtp_password'] = "password"
 gitlab_ci['smtp_domain'] = "smtp.gmail.com"
 gitlab_ci['smtp_authentication'] = "login"
 gitlab_ci['smtp_enable_starttls_auto'] = true
 gitlab_ci['smtp_tls'] = false
 gitlab_ci['smtp_openssl_verify_mode'] = 'peer'

And it just doesn't work! In gitlab-ci, the Test settings says We successfully tested the service. But I don't receive any mails!

I verified in the logs (btw, there should be more documentation on how debug gitlab-ci). I did sudo cat /var/log/gitlab/gitlab-ci/production.log | grep mail and here is the result (I took only the last lines):

  Rendered notify/build_fail_email.html.haml within layouts/notify (4.3ms)
  Rendered notify/build_fail_email.text.erb (0.5ms)
Sent mail to *****@gmail.com (2263.7ms)

But I didn't receive that mail... And no error message.

What is wrong with my configuration?