Since February 2024 Gmail and Yahoo have been checking bulk senders strictly, and since 2025 Microsoft (Outlook, Hotmail) expects much the same. If you don't comply, your emails end up in spam – or never arrive at all. The good news: the rules are clear, and you only need to set them up properly once.
1. Authentication: SPF, DKIM, DMARC
These three DNS records prove that an email really comes from you.
- SPF lists which servers may send on behalf of your domain.
- DKIM adds a digital signature to every message, so any tampering in transit shows.
- DMARC tells receiving servers what to do with messages that fail authentication, and sends you reports. Start with
p=none, watch the reports, then tighten the policy.
2. A separate (sub)domain for bulk mail
Send newsletters from something like news.yourcompany.com, and keep invoices and password resets on a separate stream. If a campaign goes wrong, it won't drag your main domain's reputation down with it.
3. Warm-up
A brand-new domain or IP address can't send ten thousand emails on day one. Start with a few hundred engaged recipients and increase the volume gradually over 2–4 weeks.
4. A clean list
- Only email people who subscribed – ideally with double opt-in (GDPR expects consent anyway).
- Remove bounced addresses immediately.
- Remove people who haven't opened anything for 6–12 months, or ask whether they still want your emails.
- Never buy a list.
5. One-click unsubscribe
The big providers expect a List-Unsubscribe header with one-click unsubscribe, and they expect requests to be honoured within two days. Put a clearly visible unsubscribe link at the bottom too – people who can't find one hit the “spam” button instead, which hurts far more.
6. Pacing and monitoring
Don't send from your web host's SMTP server or a Gmail account – use a service built for it (e.g. Amazon SES, Postmark or Brevo). Send in batches and watch your complaint rate in Google Postmaster Tools: keep it below 0.1% and never let it reach 0.3%.
Deliverability isn't a trick, it's trust: providers look at how much people actually want your emails.
If you'd like, I'll review your domain and set up the whole chain – it usually takes an afternoon.