無法GitLab與Mailgun

Question

連接

我無法發送電子郵件，GitLab，我使用的服務Mailgun，我下面的設置：

sudo vim /etc/gitlab/gitlab.rb 

設置：

gitlab_rails['gitlab_email_from'] = "username@domain.com" 
gitlab_rails['gitlab_email_reply_to'] = "username@domain.com" 

gitlab_rails['smtp_enable'] = true 
gitlab_rails['smtp_address'] = "smtp.mailgun.org" 
gitlab_rails['smtp_port'] = 587 
gitlab_rails['smtp_authentication'] = "plain" 
gitlab_rails['smtp_enable_starttls_auto'] = true 
gitlab_rails['smtp_user_name'] = "username@domain.com" 
gitlab_rails['smtp_password'] = "secret" 
gitlab_rails['smtp_domain'] = "domain.com" 

重新配置和重新啓動：

sudo gitlab-ctl reconfigure 
sudo gitlab-ctl restart 

有沒有人有任何想法如何解決這個問題？謝謝。