What do email spam filters look for

Keep a healthy ratio of text-to-images, write clean HTML, and ensure your emails create a good user experience across email clients. Remember, many email clients block images by default. Make sure your email can still be understood even with images off. You can read more about them in our post on email domain reputation here. Invest the time to make sure your marketing emails are properly authenticated. The chances are good that Gmail based addresses make up the majority of your email list.

Gmail uses a combination of rule-based filters and machine learning, most recently integrating TensorFlow based AI into their spam filter. Gmail looks at both the domain and the IP address of senders when determining where to place an email. What may be spam for you are promotions for me, and inboxed for someone else.

Continuing to use the same email cadence as you use with your most active subscribers will increase the risk that Google will deem future messages as unwanted. After that, a small number of emails are delivered to the inbox. If this initial test results in a high complaint rate, most future emails will be sent to spam. The best way to avoid emails going to spam in Gmail is to follow their list of Sender Guidelines. Item number one on their list is to use Gmail Postmaster Tools.

It can have glitches, but overall it is a handy tool for email marketers. Microsoft is one of the oldest webmail providers having launched Hotmail.

In , Microsoft rebranded Hotmail. Microsoft pays attention to engagement, complaints and spam traps and other factors similar to other email service providers, but they also rely heavily on their Sender Reputation Network. SRD may be more reliable than monitoring complaint rates alone.

Senders can easily manipulate complaint rates by sending a higher volume of email to reduce the number of complaints. As with other providers, following best practices like regularly scrubbing your list of disengaged contacts, authenticating emails, and sending high-quality and relevant content will decrease the odds your emails go to spam in Outlook.

It allows marketers to request access to their IP range and see data on subscriber complaints, email volume, spam trap hits, etc. If you are following best practices and still encountering deliverability issues, you can submit a support ticket to Microsoft directly.

Spam trigger words are phrases that email providers flag as fraudulent and malicious. These words and phrases typically overpromise a positive outcome with the goal of getting sensitive information from the recipient.

Spam filters can be triggered for a variety of reasons, causing your email to skip recipients' inboxes and land straight in their spam inbox. One of the easiest ways to avoid spam filters is by carefully choosing the words you use in your email's subject line.

Trigger words are known to cause problems and increase the chances of your email getting caught in a spam trap. By avoiding these words in your email subject lines, you can dramatically increase your chances of getting beyond the filters.

For instance, if you are offering a 3-for-1 discount sale, you can still advertise that in your emails and not get sent to spam. Email providers look for a number of factors when deciding whether to automatically send your emails to spam. Email providers only want to deliver emails from high-reputation senders. To be a high-reputation sender, do the following:. The text surrounding the spam phrase also matters, as does your history as an email sender. Next time you sit down to write an email subject line, consult the exhaustive list below.

In fact, you might want to bookmark this list so you can refer back to it every time you craft an email subject line. Here are some examples: The phrase, "extra inches" will get you a score of 3. The phrase sounds like it came from some kind of "appendage enhancement" pharma-spam, right? Turns out "Dear" will get you 2. Use something else, like "Howdy. We might stop using this example. The phrase, "stop further distribution" will get you 3. By the way—" distribution?

An efficient way to do this is to issue subscribers with a welcome email that they must confirm — either by clicking a link or pressing a button — before they are formally added to your email list. The second opt-in email can also be a way to request subscribers to whitelist you by adding you to their contact list. Being on their approved senders lists gives full assurance that your future emails will never get flagged by spam filters.

This is a simple extra step that guarantees your subscribers truly wish to hear from you. It also helps keep your email list clean and relevant — positively impacting both your reputation and standing in the eyes of inbox providers. Make it a part of your workflow to consistently audit and update your email list. This can damage your reputation and increase the odds of being relegated to spam.

In turn, if certain subscribers have not engaged with your emails for an extended period of time, consider removing them from your list. Continuously monitor your email campaign engagement and make adjustments as quickly and efficiently as possible. Key metrics to track include open rates, click through rates, delivery errors, and spam complaints.

For instance, a high number of delivery errors is a sign to clean up your email list. Or, if you have low open rates, test out different subject lines until they improve. If the issue persists, consider retooling your strategy altogether.

Additionally, persistently monitor your sender reputation to ensure your email servers IP address has not been blacklisted. There are multiple tools online that can analyze your IP address and domain to check if you have been blacklisted by any inbox providers. If you have been blacklisted, submit a request as soon as possible to be reinstated. There are also a variety of spam checking tools that can analyze your sending reputation and allocate a score — typically from 0 to The higher the score, the less likely that your emails will be flagged by spam filters.

The key driver behind every successful email marketing campaign is the dedication to sending useful, intriguing content to your subscriber base.

Never send emails just for the sake of it. If there is no clear intent behind your messages, your engagement will drop and spam rates will climb. No one likes content that is too salesy — particularly if the pitches do not match their personal tastes.