Redmine有时候新建问题 ，更新指派人的时候反应很慢， 很大原因应该是发送邮件方式不对.
　　1.一种方式是改为异步发送
email_delivery:
delivery_method: :async_smtp
smtp_settings:
address: smtp.fabao.cn
port: 25
domain: fabao.cn
#authentication: :login
#user_name:
#password:
　　2.另外检测到Redmine日志 ，会发现发送邮件失败 ，也会导致发送很慢.
start_date"=>"2016-03-24"， "due_date"=>"2016-03-25"， "estimated_hours"=>""， "done_ratio"=>"0"， "watcher_user_ids"=>["5"]}， "continue"=>"创建并继续"， "project_id"=>"baslaw"}
Current user: admin (id=1)
Rendered mailer/_issue.text.erb (2.8ms)
Rendered mailer/issue_add.text.erb within layouts/mailer (3.7ms)
Rendered mailer/_issue.html.erb (1.5ms)
Rendered mailer/issue_add.html.erb within layouts/mailer (2.3ms)
Email delivery error: execution expired
Redirected to http://192.168.36.120/redmine/projects/baslaw/issues/new?issue%5Btracker_id%5D=1
Completed 302 Found in 30249.8ms (ActiveRecord: 51.1ms)
Started GET "/redmine/projects/baslaw/issues/new?issue%5Btracker_id%5D=1" for 192.168.36.148 at 2016-03-24 16:57:39 +0800
Processing by IssuesController#new as HTML
Parameters: {"issue"=>{"tracker_id"=>"1"}， "project_id"=>"baslaw"}
Current user: admin (id=1)
Rendered issues/_form_custom_fields.html.erb (3.5ms)
Rendered issues/_attributes.html.erb (25.4ms)
Rendered issues/_form.html.erb (34.7ms)
Rendered attachments/_form.html.erb (2.9ms)
Rendered issues/new.html.erb within layouts/base (41.8ms)
Rendered plugins/redmine_code_review/app/views/code_review/_html_header.html.erb (1.6ms)
Rendered plugins/clipboard_image_paste/app/views/clipboard_image_paste/_headers.html.erb (1.9ms)
Rendered plugins/redmine_code_review/app/views/code_review/_body_bottom.html.erb (0.1ms)
Rendered plugins/clipboard_image_paste/app/views/clipboard_image_paste/_add_form.html.erb (3.3ms)
Completed 200 OK in 136.3ms (Views: 73.9ms | ActiveRecord: 13.5ms)
Started GET "/redmine/my/page" for 192.168.36.148 at 2016-03-24 16:58:01 +0800
Processing by MyController#page as HTML
Current user: admin (id=1)
　　这时候要配置系统的sendmail问题.看下具体是哪里出了问题 .