Yellaro
← All posts

Why your emails go to spam (and how to fix it)

You hit send on a newsletter, and half your readers never see it. It's sitting in spam, or in Gmail's Promotions tab, or it just silently vanished. Nothing told you. Your open rate dropped and you assumed people lost interest.

Most of the time it isn't your writing. It's a handful of technical signals that decide, before anyone reads a word, whether your email is trusted. Here's what actually controls it, in rough order of how often it's the culprit.

You haven't set up authentication

This is the big one. Inbox providers want proof that an email claiming to be from you actually is. That proof comes from three DNS records: SPF, DKIM, and DMARC.

  • SPF lists which servers are allowed to send for your domain.
  • DKIM adds a cryptographic signature so receivers can verify the message wasn't forged or altered.
  • DMARC ties the two together and tells inbox providers what to do when a message fails.

If these are missing or misconfigured, Gmail and Outlook treat your mail with suspicion by default. Since February 2024, Google and Yahoo require them outright for anyone sending in bulk. No authentication, no inbox.

You can check your own domain in a minute with our free DMARC checker, SPF checker, and DKIM checker. If any come back missing, that's very likely your problem right there.

Your domain has no reputation yet

Inbox providers track a reputation score for every sending domain, based on how recipients react to your mail. A brand new domain, or one that's never sent bulk email, starts from zero. Zero reputation means "we don't know you," and unknown senders get filtered hard.

This is why your first few campaigns from a new domain often land in spam even when everything is configured correctly. It's not broken. It's that trust is earned over time, through people opening, reading, and not marking you as spam. The fix is patience and good sending habits, not a setting.

You're sending to people who didn't ask

The fastest way to wreck deliverability is emailing people who don't want it. Bought lists, scraped addresses, or contacts who forgot they signed up all produce the same result: low opens, high spam complaints, and bounces to addresses that don't exist. Inbox providers read all of that as "this looks like spam," and they're not wrong.

Double opt-in (where a subscriber confirms by clicking a link before they're added) is the single best protection. It's a small amount of friction that keeps your list clean and your reputation intact. A smaller list of people who actually want your email outperforms a big list of people who don't, every time.

You're not handling bounces and complaints

Every list accumulates dead addresses and people who hit "spam." If you keep emailing them, providers assume you're not paying attention, which is exactly what real spammers do. You need to stop sending to hard bounces immediately, and remove anyone who marks you as spam. If you're running your own setup, this means wiring up bounce and complaint feedback from your sending provider and acting on every event. Most people never get this configured, and their reputation slowly bleeds out.

Small things that still matter

  • A "from" address on your own domain, not a free Gmail or Yahoo address. Bulk mail from a free address is a strong spam signal now.
  • A working unsubscribe link, ideally a one-click List-Unsubscribe header. Required by the 2024 bulk-sender rules, and hiding it just drives people to the spam button instead, which is far worse for you.
  • Not sending a sudden huge spike from a domain that normally sends little. Ramp volume up gradually.
  • Plain, honest subject lines. Spammy phrasing and ALL CAPS still get filtered.

The uncomfortable summary

Deliverability isn't one fix. It's authentication set up correctly, a clean opted-in list, bounce and complaint handling, a domain reputation built patiently, and steady sending habits. Each piece is manageable on its own. Together, they're a part-time job, and it's the job that sits between you and the inbox.

That's the part Yellaro takes off your hands. We run managed newsletter hosting with SPF, DKIM, DMARC, bounce and complaint handling, and reputation-managed sending built in, so your mail is set up to land from day one. You write the email. We handle the part that decides whether anyone sees it. See how it works, or start by checking your domain.