You send a quote and hear nothing. You call and the customer says: sorry, your email was in spam. Familiar? You are not alone. Since Google and Yahoo introduced stricter sender rules in 2024, emails from poorly configured domains have ended up in spam more regularly. The problem is not your writing: mailbox providers cannot verify you are who you claim to be. The good news is that this is almost always fixable, usually within an afternoon and often without doing anything technical yourself. This article explains what is happening and exactly what to ask your hosting provider or IT partner.
Emails going to spam? Help them reach your customers
31 July 2026 · 6 min read · Marketing Scan
Editorially updated:
This article was translated from Dutch.
In this article
How large is the problem really?
Larger than most business owners think. An average, well-configured email programme reaches the inbox around 89% of the time. However, senders failing Gmail and Yahoo's rules introduced in February 2024 see 22 to 34% of emails land in spam, compared with 5 to 10% with correct settings. That is 1 in 3 quotes, invoices or newsletters your customer never sees.
This affects more than large senders. Two years after the rules arrived, around 30% of senders still do not fully comply with at least a requirement. Small businesses are overrepresented simply because nobody ever checked. The domain was registered years ago, email worked and everything stayed unchanged.
Why spam filters have become stricter
The reason is simple: phishing has exploded. In Belgium, Safeonweb received almost 10 million suspicious-message reports in 2025, rising to over 40.000 reports daily in early 2026. Mailbox providers such as Gmail and Outlook protect users by checking senders much more strictly.
A spam filter essentially asks a few questions. Does this email really come from the domain in the sender address? Does that domain have a good reputation or do recipients frequently complain? Can newsletter recipients unsubscribe easily? If the filter cannot answer positively, it chooses the safe option: spam. Your email becomes collateral damage in the fight against fraudsters.
Your email's identity card, in plain English
Behind the scenes, three settings prove your emails really come from you. You need not remember their names, but understanding their roles helps:
- SPF is a list attached to your domain saying which computers may send on your behalf. If your newsletter tool or accounting software is absent, recipients distrust those messages.
- DKIM is a digital signature proving nobody altered your email in transit.
- DMARC tells recipients what to do with messages pretending to use your domain without really coming from you: reject them or allow them?
The last setting also protects against abuse. Of 5,5 million scanned domains, only 12,8% effectively block forged messages using their name in early 2026. For the others, a fraudster can technically send as though they were the company itself. Correctly configured email therefore protects both delivery and your name.
The five most common causes at small businesses
The same problems recur in practice:
- Missing or incomplete settings. The domain lacks SPF, DKIM or DMARC, or has only some. This is by far the most common cause.
- Forgotten new tools. You started sending through a newsletter or invoicing tool, but nobody added that service to your domain settings.
- A free address containing your business name. An address such as yourbusiness@gmail.com has no independent domain reputation to build and looks less professional.
- Purchased or old address lists. Bounces and spam complaints destroy reputation faster than you build it. Gmail uses a maximum of 0,3% spam complaints; above that, your messages collectively go to spam.
- No easy unsubscribe button. Anyone unable to unsubscribe in a click chooses 'this is spam'. Every complaint counts.
Fix it without technical knowledge
You need not configure this yourself. Here is what you can do:
- Test first. Send an email to a free service such as mail-tester.com and check the score. Below 8 out of 10 needs work.
- Call your hosting provider or IT partner and ask directly: are SPF, DKIM and DMARC correctly configured for our domain and every service we send through? A good provider often handles this free or for a small fee.
- List your senders. Note every tool sending for your domain: mailbox, newsletter software, online shop, invoicing and accounting. Share that list.
- Clean your address list. Remove addresses that have opened nothing for months and email only people who requested it.
- Check your unsubscribe link. Every commercial email needs a working unsubscribe mechanism operating in a click.
Allow a specialist half a day. Compared with losing a third of your quotes, it is among the highest-return marketing investments.
What happens when email simply arrives
Email delivery sounds technical, but it directly affects revenue. Over 85% of Belgian internet users search online for information about products and services, and the subsequent contact almost always uses email. Every message reaching the inbox instead of spam means a quote read, an invoice paid on time or a newsletter that actually sells.
You also notice improvements quickly: domain reputation recovers within weeks once settings are correct and complaints decline. Leaving the problem unresolved digs the hole deeper: the longer you send from a poorly configured domain, the more filters distrust you.
Check your domain today
Do you know whether your emails arrive? Most business owners discover problems only when a customer happens to mention them. There is a smarter approach. The free marketing scan checks your domain, website and online visibility within minutes, including trust signals influencing whether customers and spam filters believe you. Free, in plain English, with practical next steps.
Frequently asked questions.
Why are my emails suddenly going to spam when they used to work?
Google and Yahoo introduced stricter sender rules in February 2024 and enforce them increasingly strictly. Domains without correct SPF, DKIM and DMARC settings are now distrusted even if nothing changed at your end. Ask your hosting provider to check; it is usually fixed quickly.
How do I test my email settings myself?
Send a test email to a free service such as mail-tester.com and review the score. You can also send to your own Gmail address, click the three dots and choose 'Show original' to see whether SPF, DKIM and DMARC say 'pass'. A failure or missing result needs your provider's attention.
Do Google and Yahoo's rules apply to my small business?
The strictest rules formally apply above 5.000 emails daily, but spam filters assess every domain using the same signals in practice. Even with ten messages daily, an unidentified domain can land in spam. Basic configuration is worthwhile for every business.
What does fixing this cost?
The settings themselves are free: records added to your domain. At most, you pay for an hour of your hosting provider's or IT partner's work, often between 0 and 150 euros. Compared with unread quotes disappearing into spam, it pays for itself almost immediately.
Does asking customers to add me to their contacts help?
It helps slightly for that customer because messages from known contacts arrive more often. It does not fix the cause: new prospects do not have you in their address book. Structurally sound email configuration works for everyone, including people who do not know you yet.
Sources for this article
How does a marketing scan work? Audit methodology
Turn advice into action for your website
Create a free account. Save your website in your dashboard and follow its score and improvements in one place.
Create your free account