If your emails are not reaching inboxes, you are wasting your budget. This guide covers how spam filters work and what you can do to keep your campaigns out of the junk folder.
What are spam filters?
Email providers like Gmail, Outlook, and Yahoo Mail use spam filters to protect their users. Incoming emails are analysed, and the ones that pass go to the inbox. The ones that fail go to spam or get blocked entirely.
Years ago, filters mainly scanned email content for spammy words and formatting. That has changed. Providers now look at how their users have engaged with your previous campaigns, opens, replies, deletions, and more, and use that history to decide where your next email lands.
What you want your subscribers to do with your emails
- Open your emails. Frequent opens signal to inbox providers that your mail is worth receiving, which improves your sender reputation over time.
- Reply to your emails. A reply is a strong positive signal. Providers know people do not reply to spam.
- Mark your email as not junk. When a subscriber moves your email out of the junk folder, providers treat this as a clear vote of confidence in your content.
- Move your email to other folders. Filing an email away shows the recipient cares about it. Providers read this as a good sign and are more likely to keep delivering your mail.
- Add you to their address book. This tells providers that the recipient actively wants your emails, which helps your reputation considerably.
What you do not want your subscribers to do
- Move your email to junk. This is a direct negative signal. Enough of these and providers will start filtering your campaigns before they reach anyone.
- Delete without opening. When recipients bin your email unopened, providers register it as a sign that the mail was unwanted.
How to avoid spam filters
1. Only email people who opted in. Buying email lists is a fast way to damage your sender reputation and your brand. Build your list organically, offer a genuine incentive like useful content or an exclusive discount, and make it easy for people to subscribe. A smaller, engaged list will always outperform a large, bought one.
2. Use a recognisable from name. The from name is one of the first things a subscriber sees, and it drives open rates. Use a name your recipients will recognise. If we sent the TouchBasePro newsletter from "Victoria Simpson" instead of "TouchBasePro", a big chunk of our audience would not know who it was from and would not open it.
3. Use a real reply-to address. Avoid noreply@companyname.com addresses. A real reply-to address lets subscribers respond, which as noted above is a positive signal for deliverability. It also opens a direct line of conversation with your customers, which is worth having on its own.
4. Send targeted, segmented campaigns. A spray-and-pray approach hurts your engagement rates, which hurts your reputation. Segment your database and send tailored emails to each group. Relevant emails get opened and acted on, and that engagement feeds back into your sender score.
5. Implement DMARC on your domain. DMARC (Domain-based Message Authentication, Reporting, and Conformance) authenticates your sending domain and stops bad actors from spoofing it. Through Sendmarc, TouchBasePro can implement DMARC on your domain. Get in touch if you want to know more about protecting your email domain.
Deliverability does not always get the attention it deserves when you are planning a campaign, but it underpins everything. Keep these points in mind when you build your next send, and contact us if you need a hand with your email marketing.
Frequently asked questions
- How do spam filters decide if an email goes to the inbox or junk folder?
- Spam filters analyse both the content of your email and the engagement history your subscribers have with your previous campaigns. If recipients regularly open, reply to, or save your emails, providers treat that as a positive signal. If they delete without opening or move emails to junk, that works against you.
- Does buying an email list affect my deliverability?
- Yes, negatively. Purchased lists are full of people who never opted in to hear from you. High spam complaints and low engagement from those addresses will damage your sender reputation, making it harder to reach even the subscribers who do want your emails.
- Why should I avoid using a noreply email address?
- Replies from subscribers are a positive engagement signal that inbox providers use to assess your reputation. A noreply address blocks that signal entirely. It also removes a channel through which customers might reach out to you directly.
- What is DMARC and why does it matter for email marketing?
- DMARC (Domain-based Message Authentication, Reporting, and Conformance) is an email authentication protocol that verifies your sending domain and prevents other parties from spoofing it. Implementing DMARC helps protect your brand reputation and can improve deliverability by showing inbox providers that your emails are genuinely from you.