Email deliverability in plain language
The problem
"I send ordinary, correct mails to real customers, and yet half of them end up in spam." That's the frustration many business owners and office managers run into. No error message comes back, customers call to say they received nothing, and you're left guessing where it goes wrong.
Deliverability is about that whole journey from your send button to the other person's inbox. Along the way, the receiving server judges whether your message can be trusted. If it gets too few or the wrong signals, your mail goes to the junk folder, or is silently rejected. That feels unfair when your content is perfectly fine.
Why does this happen?
The receiving server doesn't so much look at what you write, but at who you are and how you send. Four factors weigh the heaviest.
- Authentication. Without correct SPF, DKIM and DMARC, the recipient can't verify that you're really allowed to mail on behalf of your domain. Then trust falls away.
- IP reputation. If you send via a server whose IP address has been used for spam before (think cheap, shared hosting), you inherit that bad name.
- Content. Lots of links, just a big image without text, or typical "free!" language raise your risk.
- Volume and pattern. Suddenly hundreds of mails from an address that normally sends little looks suspicious.
In practice it's almost always the first two, authentication and reputation, that push neatly sent mail into spam anyway. That also explains why the feeling "but I'm doing everything right" is correct: your content is fine, but the recipient looks first at the signals underneath.
Handy to know: there's a difference between mail that ends up in spam and mail that doesn't arrive at all. In the first case your message does reach the mailbox, but in the junk folder; in the second case it's rejected or vanishes without a trace. The causes largely overlap, but the distinction helps you find the right lever faster.
How to fix it
The approach falls into two parts: what you control yourself, and what your provider should take care of.
What you do yourself:
- Write ordinary, personal messages. Keep a balance between text and images.
- Only send to people who expect your mail.
- Build larger sends up gradually rather than sending hundreds of mails at once.
What your provider should carry:
- Set up SPF, DKIM and DMARC correctly and keep them up to date. If you want to understand how they work together, read the guide on setting up SPF, DKIM and DMARC together.
- Send via IP addresses with a good reputation, and guard that reputation.
- Correct reverse DNS (PTR) so the IP address points neatly to the mail server.
Not sure which records all belong to it? The explanation of DNS records for email lines up MX, SPF, DKIM and DMARC.
The line between "do it yourself" and "have it taken care of" is exactly where many people get stuck. You can tweak text and sending behaviour right away. But DNS, authentication and reputation require access, knowledge and maintenance, and those three determine the largest part of your deliverability. Choose a provider that manages this, and the hardest part falls away, leaving you only the writing and sending.
Checklist for better deliverability
Work through these points if your mail keeps getting stuck:
- SPF, DKIM and DMARC are set up correctly for your domain.
- You send via a server with a good IP reputation.
- Reverse DNS (PTR) points to your mail server.
- Your messages are personal, with text and images in balance.
- You only send to recipients who expect your mail.
- For larger mailings you build the volume up gradually.
If your mail specifically lands in the junk folder, also work through the approach in why your mail ends up in spam.
How Mailflux takes care of your email deliverability
At Mailflux you don't have to tinker with deliverability yourself. We manage SPF, DKIM and DMARC and guard the IP reputation of our sending servers, so your mail sends the right signals to the recipient. On top of that, every plan filters with machine learning against spam, phishing and malware, with antivirus, antispam and antimalware as standard.
You get professional email on your own domain, hosted in Europe and GDPR-compliant, with automatic backups and optional two-factor authentication. That way your attention stays on your work instead of on DNS records.
FAQ
Frequently asked questions
What exactly does email deliverability mean?
Deliverability is the likelihood that your message actually arrives in the inbox instead of in spam or nowhere. It depends mainly on authentication (SPF, DKIM, DMARC) and the reputation of the sending server, not so much on the content of your text.
Why does my tidy mail still end up in spam?
Usually because of the technology behind the scenes. Missing or incorrect authentication, or a sending server with a weak IP reputation, give the recipient too little trust. Fix those signals and your mail typically just comes through.
Can I improve deliverability myself?
Partly. You write personal mails and only send to those who expect it. But authentication and IP reputation sit with your provider. If it chooses well there, that takes the hardest part off your hands.