Most content filters today are comprehensive; they look at content fingerprints as opposed to following hard and fast rules. A few years ago, having punctuation or all capital letters in a subject line meant that your email was likely to be sent straight to the spam folder. Now, it’s more about the combination of different content characteristics, and whether that combination has been commonly seen in spam. You can use Spam Assassin or a third-party reputation service such as Return Path to help identify content issues.
Checking the URLs that you use in your emails against blacklists can provide very useful information, because some ISPs will block email with blacklisted links. URIBL.com and SURBL.org are two very useful sites that you can use to determine whether your links are listed. Remember to check any links provided to you by a third party or any link shorteners, which have become increasingly dangerous because they obfuscate the final domain.
Avoid broken links in your emails; make sure that you actually have pages behind your links. If you have an unsubscribe link, make sure that it works. It’s easy to forget to test every single link when you’re building out new email programs or changing existing email templates.
Make sure that the Privacy and Terms pages work on your site. Recipients may not trust your email if they can’t find the standard fine print on your site, which will diminish your email’s value and deliverability potential.
If you’re sending high frequency content (e.g., daily deals), ensure that the content is actually different each day. With higher cadence comes greater responsibility to ensure that the content is timely and relevant.
大部分当今的内容过滤系统已经比较全面，它们会查看邮件内容特征，而不是仅仅一些死板固定的规则。几年前，还只是检查邮件标题上的单词和符号的相似度来确定是否直接放入垃圾收件箱。现在会更加全面的综合各种内容特征来判断是否是垃圾邮件。你可以使用Spam Assassin或者其他第三方信用检测服务，例如通过Return Path来确认实际发信方。
Despite the challenges of navigating the various systems between you and your target recipients, email can be an incredibly effective communication mechanism if you use it correctly. We hope that you now have a better grasp of what factors influence whether your email reaches your target inboxes, and that you also have a list of things you can do to make your email program better.
While the list above is by no means a comprehensive list of absolutely everything you can do to help your email quality (and therefore its deliverability), we hope that you find it a good place to start. As you build out your email program, you need to remember two vital things:
If you take care of these two things by following these tips, your email program will be well on its way to success!