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Your marketing campaign email was planned to the last word, the embedded images were inspiring… and it ended up in everyone’s spam filters. This article explains how to avoid email spam filters by setting out how they work, so your valid emails don’t get filtered out by mistake.

Why is this important for your business?

How often have you waited for an email with a login or some other important piece of information, and had to go rummaging for it in your junk folder? If your business is sending out important account information or other important emails and your clients never get them, you have a business problem.

Although the variety of criteria that spam filters utilise to identify and separate spam is undoubtedly beneficial for everyone, it can make it more difficult to create legitimate business emails that reach their intended recipients.

To maximise the return on your investment in staff time and money spent on generating and sending marketing emails and company communications, it is essential to learn how to avoid email spam filters.

Why are spam filters necessary?

It is much easier to notice our important emails when we filter out the undesirable ones. Keep in mind that mailbox providers have a financial incentive to keep customers using their service, and an efficient spam filter can facilitate this.

Spam filters are crucial they are to organisations to prevent cybercrime. They stop phishing emails, which are far and away the most common means of carrying out successful hacks. According to several surveys, more than 90% of malware is delivered in spam emails, while approximately 50% of the world’s email is recognised to be spam.

For instance, Gmail’s filtering mechanism blocked more than 100 million phishing emails a day in 2020, and statistics from September 2020 indicate that 88.88 billion spam emails were being sent daily around the world, according to data company Statista. As a result, email filtering is required to prevent spam and potentially harmful emails like phishing from clogging up our inboxes.

How do spam filters actually work?

To learn how to avoid email spam filters, you basically need to know how they work.

Spam filters vary in design between mailbox providers. They classify emails as spam, and direct them to your spam folder, using a variety of the different signals and scores listed below. Companies can configure their spam filters to a certain extent.

  1. In messages, suspicious word patterns and frequencies are detected via Bayesian filters (and other heuristic filters).
  2. Emails from senders who have been identified as spammers are blocked and removed by blocklist filters.
  3. Content filters, as their name implies, examine an email’s wording for words like “special offer”, “free” and “discount,” which spammers frequently employ, as well as for any other prohibited language. There are also “language filters,” although these are meant to weed out messages that are written in a language other than the one the recipient has specified.
  4. Header filters analyse an email’s credibility based on its header’s features and technical information, such as the IP address.
  5. Rule-based filters evaluate incoming emails against rules set by users to determine whether to transmit them to the spam filter rather than the inbox. These guidelines can, for instance, be based on the message’s or the header’s words or phrases.
  6. Rates of engagement are sometimes used. For instance, if a high number of emails is sent, not opened, then removed from a sender mailbox, this is classified by the standard marketing term “low engagement”. It basically means people aren’t interested in this email and it’s an indication of spam. In some systems this will cause an email to be filtered out.
  7. Low levels or sporadic levels of mail exchange can be a warning sign. It can be assumed that an email account is spam-related if it is only used sometimes to send out large quantities of emails at once.
  8. Emails frequently end up in the inbox or the spam bin for identification and reputation reasons, not just because of the content of the email. A reputation score indicates how reliable emails you’re your organisation tend to be. If your marketing department uses a scattergun approach to emailing possible leads, your tactics could end up backfiring.
Close-up of a smartphone screen displaying app icons with a focus on the mail app icon showing 20 unread emails, emphasizing the need for effective spam filters.

How to stop your company emails landing in spam filters

The majority of us aren’t spammers and have genuine marketing, commercial, and personal communications that we need to make sure reach their intended recipient.

Below, we list how to avoid email spam filters in 10 steps!

  1. Ask trusted people to add your email address to their contact list or to whitelist your address in their spam filter, as most major email providers (Google, Yahoo, and Microsoft) automatically exempt whitelisted addresses from further scanning.
  2. Use DMARC email authentication, Sender Policy Framework (SPF), and DomainKeys Identified Mail (DKIM). Examples of more technical techniques to show that your emails are not spam include adding DKIM signatures to emails as an encrypted header, using SPF records to link emails back to the domain, and using the DMARC protocol to guard against unauthorised use of your domain, such as spoofing.
  3. Avoid using spam trigger terms in the email’s header and body. These include “double your,” “XXX,” “earn,” “cash bonus,” and so on. There are numerous lengthy lists of spam trigger words available online, and the general rule is to stay away from anything that is sensationalising or overly optimistic. Such extravagant terminology is banned by the financial regulator in most of the financial sector which is why these words are never part of legitimate communications from banks, building societies or any other form of financial institution.
  4. Add recipient-specific information to emails, such as their first name. This suggests that the likelihood of the email being unsolicited is reduced.
  5. Steer clear of wacky font formatting, unusual punctuation, or bizarre sentence structure in an attempt to stand out. These are all typical indications of spam.
  6. Maintain high email deliverability rates by, for example, keeping your email list clean (removing inactive users and invalid emails), ensuring that emails adhere to current web regulations, and including compelling copy.
  7. Only offer connections to trustworthy websites.
  8. Incorporate a link or button for unsubscribing in marketing mailings.
  9. Be mindful of your language and spelling. Use spellcheckers and proofread communications. Phishing emails deliberately employ spelling mistakes to filter out the more educated and likely more perceptive members of society, and to filter in the most vulnerable. The criminals who send phishing emails do not want to move to the next step of their scam, which involves direct interaction and is time-consuming, if their victim will smell a rat before the conclusion of their crime.
  10. Make sure the name listed as “sent from” can be recognised quickly and easily, such as your name and the name of your company.
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Flywheel IT Services has teams of highly qualified and experienced IT engineers and consultants around the UK. For over 20 years we have partnered with businesses, schools and major construction companies to guide and support their projects, tech strategies and day-to-day operations.

In an average year we help 200 businesses use technology for fast-track growth, we design sustainable ICT infrastructures for 100 new schools and commercial buildings, and we nurture the ICT resources and dreams of 33,000 school children.

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