Ruby on rails Rails应用程序在DigitalOcean上使用Ubuntu通过SendGrid发送联系人电子邮件

当某人填写表单时，尝试将消息发送到某个地址。但我有一个错误：

Errno::ECONNREFUSED in SupportrequestsController#create
Connection refused - connect(2) for "smtp.sendgrid.net" port 587

@supportrequest = Supportrequest.new(params[:supportrequest])

     if @supportrequest.save  <---GETTING ERROR HERE
        HydraNotifier.send_support_email(@supportrequest).deliver
        flash.now[:error] = nil
        redirect_to( contact_path, :notice => 'email sent')

---

DigitalOcean很可能正在阻止SMTP端口。联系那里的支持人员，要求他们删除该块，或者切换到通过HTTPS发送。我与DigitalOcean和SendGrid进行了交谈。他们俩都没有解决我的办法。但不管出于什么原因，它今天开始工作。

config.action_mailer.delivery_method = :smtp  
ActionMailer::Base.smtp_settings = {
    :address => "smtp.sendgrid.net",
    :port => 587,
    :user_name => ENV['SENDGRID_USER'],
    :password => ENV['SENDGRID_PASS'],
    :domain => "mydomain.com",
    :authentication => :plain,
    :enable_starttls_auto => true
  }