Inbox Pros Blog   »   Content Filtering and its Impact On Email Deliverability

June 8, 2015

Content Filtering and its Impact On Email Deliverability

Author | Inbox Pros


So what is content filtering exactly?

Content filtering, involves the use of a program designed to filter and prevent access to certain content deemed objectionable, or content which could be harmful if opened or accessed. The most common items to filter are executables, emails or websites. Content filtering is used by corporations as part of Internet firewall computers and also by home computer owners, especially by parents to screen the content their children have access to from a computer. Content filtering can also impact email deliverability, as some content could potentially be blocked or filtered as spam.


So, what causes some emails to be blocked or filtered?

Unfortunately, it is fairly common for legitimate emails to be blocked or moved to the Junk folder by ISPs. Here are a few common reasons ISPs block or filter certain emails…

Spammy Looking Content

Spam emails are often easy to recognize: misspelled subject, subject lines written in all caps, purely promotional in nature, and often with an unknown email address in the “from” field.

Subject Lines

Subject lines are critical to email deliverability. Avoid words like “free,” “act now,” “limited time,” or “click now.” Again, subject lines with an excessive amount of punctuation and capital letters often triggers spam filters.

IP Address

Some spam filters will flag your email campaigns if anyone with the same IP address has sent spam. That means that if someone who shares your server is spamming, it could adversely affect your email deliverability.

Content and Format

Objectionable email content or content deemed harmful is often blocked or filtered. Make sure your content is clear, concise, and avoid topics that could trigger spam filters. It is also very important to pay attention to the links contained within your email message. Test to make sure your links are valid and avoid link shorteners. If your email message happens to contain a link from a blocked domain, there is a chance it could get filtered or blocked solely because of the link itself.

Content filtering serves an important purpose. It protects our home and work computers from harmful or damaging content, however occasionally legitimate emails never reach their intended recipients. While there are many ways to improve your email deliverability, avoiding spam and filtering triggers is a great place to start.

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