@hexawing 楼主，我也遇到邮件问题了，我们公司也是 263 的企业邮箱，配置了 ActionMailer 之后，邮件死活发不出来，能帮我看一下嘛？

Net::OpenTimeout: execution expired
    from /opt/gitlab/embedded/lib/ruby/2.3.0/net/smtp.rb:542:in `initialize'
    from /opt/gitlab/embedded/lib/ruby/2.3.0/net/smtp.rb:542:in `open'
    from /opt/gitlab/embedded/lib/ruby/2.3.0/net/smtp.rb:542:in `tcp_socket'
    from /opt/gitlab/embedded/lib/ruby/2.3.0/net/smtp.rb:552:in `block in do_start'
    from /opt/gitlab/embedded/lib/ruby/2.3.0/timeout.rb:101:in `timeout'
    from /opt/gitlab/embedded/lib/ruby/2.3.0/net/smtp.rb:551:in `do_start'
    from /opt/gitlab/embedded/lib/ruby/2.3.0/net/smtp.rb:521:in `start'
    from /opt/gitlab/embedded/service/gem/ruby/2.3.0/gems/mail-2.6.4/lib/mail/network/delivery_methods/smtp.rb:113:in `deliver!'
    from /opt/gitlab/embedded/service/gem/ruby/2.3.0/gems/mail-2.6.4/lib/mail/message.rb:2149:in `do_delivery'
    from /opt/gitlab/embedded/service/gem/ruby/2.3.0/gems/mail-2.6.4/lib/mail/message.rb:237:in `block in deliver'
    from /opt/gitlab/embedded/service/gem/ruby/2.3.0/gems/actionmailer-4.2.7.1/lib/action_mailer/base.rb:543:in `block in deliver_mail'
    from /opt/gitlab/embedded/service/gem/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/notifications.rb:164:in `block in instrument'
    from /opt/gitlab/embedded/service/gem/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/notifications/instrumenter.rb:20:in `instrument'
    from /opt/gitlab/embedded/service/gem/ruby/2.3.0/gems/activesupport-4.2.7.1/lib/active_support/notifications.rb:164:in `instrument'
    from /opt/gitlab/embedded/service/gem/ruby/2.3.0/gems/actionmailer-4.2.7.1/lib/action_mailer/base.rb:541:in `deliver_mail'
    from /opt/gitlab/embedded/service/gem/ruby/2.3.0/gems/mail-2.6.4/lib/mail/message.rb:237:in `deliver'
    from /opt/gitlab/embedded/service/gem/ruby/2.3.0/gems/actionmailer-4.2.7.1/lib/action_mailer/message_delivery.rb:85:in `deliver_now'
    from (irb):1
    from /opt/gitlab/embedded/service/gem/ruby/2.3.0/gems/railties-4.2.7.1/lib/rails/commands/console.rb:110:in `start'
    from /opt/gitlab/embedded/service/gem/ruby/2.3.0/gems/railties-4.2.7.1/lib/rails/commands/console.rb:9:in `start'
    from /opt/gitlab/embedded/service/gem/ruby/2.3.0/gems/railties-4.2.7.1/lib/rails/commands/commands_tasks.rb:68:in `console'
    from /opt/gitlab/embedded/service/gem/ruby/2.3.0/gems/railties-4.2.7.1/lib/rails/commands/commands_tasks.rb:39:in `run_command!'
    from /opt/gitlab/embedded/service/gem/ruby/2.3.0/gems/railties-4.2.7.1/lib/rails/commands.rb:17:in `<top (required)>'
    from bin/rails:9:in `require'
    from bin/rails:9:in `<main>'

以上是报错信息