Gmail and Outlook have tightened their spam filters significantly. Here's what every marketer needs to know to keep their campaigns landing in the inbox.
In 2024, Google and Yahoo introduced mandatory sender authentication requirements. In 2025, Microsoft followed with stricter Outlook filtering. In 2026, AI-powered spam detection has made it harder than ever to land in the inbox - even with legitimate, opted-in lists.
This guide covers everything you need to know to maintain strong deliverability in 2026.
Before you send a single email, these three DNS records must be in place:
SPF tells receiving mail servers which IP addresses are authorised to send email on behalf of your domain.
TXT record: v=spf1 include:_spf.marketrixai.com ~allDKIM adds a cryptographic signature to every email, proving it hasn't been tampered with in transit.
DMARC tells receiving servers what to do when SPF or DKIM fails. Start with `p=none` (monitoring mode), then graduate to `p=quarantine` and finally `p=reject`.
TXT record: v=DMARC1; p=reject; rua=mailto:[email protected]MarketrixAI Campaigns automatically configures SPF and DKIM for your sending domain when you add it in Settings → Sending Domains.
Your sender reputation is a score (0–100) assigned to your sending IP and domain by mailbox providers. It's based on:
Purchased lists are full of spam traps, invalid addresses, and people who never opted in. A single campaign to a purchased list can permanently damage your sender reputation.
Use MarketrixAI's built-in list hygiene tool to remove:
Never send 10,000 emails from a brand-new domain. Start with 50/day, double every 3 days, and reach full volume over 4–6 weeks.
AI spam filters now detect generic "Hi {firstName}" personalisation. Use dynamic content blocks that vary based on industry, company size, or behaviour.
Google Postmaster Tools and Microsoft SNDS give you real-time visibility into your sender reputation. Check them weekly.
Deliverability in 2026 requires both technical hygiene and behavioural best practices. The good news: if you follow these rules and use a platform that handles the technical heavy lifting, landing in the inbox is very achievable.
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