ps：使用docker安装gitlab参考：https://blog.csdn.net/blog_zxb/article/details/95626093  

$ vi /etc/gitlab/gitlab.rb

// 配置gitlab邮箱
### Email Settings
gitlab_rails['gitlab_email_enabled'] = true
gitlab_rails['gitlab_email_from'] = '[email protected]'
gitlab_rails['gitlab_email_display_name'] = 'gitlab.notice'
gitlab_rails['gitlab_email_reply_to'] = '[email protected]'
gitlab_rails['gitlab_email_subject_suffix'] = 'gitlab'


### GitLab email server settings
###! Docs: https://docs.gitlab.com/omnibus/settings/smtp.html
###! **Use smtp instead of sendmail/postfix.**
gitlab_rails['smtp_enable'] = true
gitlab_rails['smtp_address'] = "smtp.qq.com"
gitlab_rails['smtp_port'] = 465
gitlab_rails['smtp_user_name'] = "[email protected]"
gitlab_rails['smtp_password'] = "xxx"
gitlab_rails['smtp_domain'] = "smtp.qq.com"
gitlab_rails['smtp_authentication'] = "login"
gitlab_rails['smtp_enable_starttls_auto'] = true
gitlab_rails['smtp_tls'] = true

// 测试
$ gitlab-rails console
$ irb(main):001:0> Notify.test_email('[email protected]', '邮件标题', '邮件正题').deliver_now