自从整站迁移后，wordpress的 contact form 7出现故障，表现为可正常接受客户输入的文字信息，但无法获取 post_url 和 post_title， 这两个标签分别是 访问网址 和 页面标题。小事不小，我为此失去两个客户询单，其实问题不大，主要难点在于排查故障，毕竟Wordpress现在是越来越臃肿庞大。初步怀疑是插件兼容性问题，之后是迁移后的环境变化问题，都无果。
最后终于找到了，原来的 contact form 7插件默认提示用的标签是[post_url] 和 [post_title]而且工作正常。但新版本改为 [_post_url]和[_post_title] ，没错就是前面多加一个“_”。注意，这些标签在 Contact Form DB 这个插件后台看还是只显示标签而非超链接和标题名，得在收到的邮件里面才会显示。
附官网的一些标签
| TAG | THIS TAG WILL BE REPLACED BY … |
|---|---|
[_remote_ip] |
the sender’s client IP address. |
[_user_agent] |
the sender’s user agent information. |
[_url] |
the URL of the contact form. |
[_date] |
the date of the submission. |
[_time] |
the time of the submission. |
[_post_id] |
the ID of the post which contains the contact form. |
[_post_name] |
the name (slug) of the post which contains the contact form. |
[_post_title] |
the title of the post which contains the contact form. |
[_post_url] |
the permalink of the post which contains the contact form. |
[_post_author] |
the author name of the post which contains the contact form. |
[_post_author_email] |
the author email of the post which contains the contact form. |
[_serial_number] |
a numeric string whose value increments. Requires Flamingo 1.5+ be installed. |