In 2026, reaching the inbox has become a major challenge. Mailbox providers — Google, Microsoft, Yahoo — have significantly strengthened their spam filters. For businesses, sending is no longer enough: the whole digital communication strategy needs rethinking.
Stricter ISPs: what has changed
Since late 2024, the major ISPs have introduced drastic rules:
- Google (Gmail) : a maximum complaint rate of 0.1%, mandatory DMARC authentication and one-click unsubscribe
- Microsoft (Outlook/365) : filtering based on the reputation of the whole domain, not just the IP. New domains are quarantined by default
- Yahoo/AOL : aligned with Google's standards, with systematic rejection without SPF, DKIM and DMARC
Key takeaway: ISP filters change every 6 months. What worked in 2024 no longer works in 2026. Keeping a close watch on the technology is essential.
SPF, DKIM, DMARC: necessary but not sufficient
These authentication protocols are now the bare minimum. Without them, your emails are rejected on sending. But having them no longer guarantees the inbox.
ISPs now analyse:
- The historical reputation of your domain (not just the IP)
- Your sending patterns : volume, regularity, gradual ramp-up
- Therecipient engagement : open rates, clicks, replies
- The content : text-to-image ratio, suspicious links, similarity to known spam
Best practices for 2026
- Gradual warm-up : increase sending volume slowly over 2 to 4 weeks to build reputation
- Advanced segmentation : target only engaged contacts and remove inactive ones after 30 to 60 days
- Dedicated infrastructure : separate transactional and marketing streams on distinct domains and IPs
- Real-time monitoring : track feedback loops, bounces and inbox placement rates
Beyond email: the multichannel strategy
Faced with stricter ISPs, high-performing companies diversify their communication channels:
- SMS marketing : open rates above 95%, ideal for urgent promotions and reminders. Data-protection rules such as the GDPR require explicit consent
- WhatsApp Business API : conversational messaging with approved templates, perfect for customer support and notifications
- Push notifications : instant engagement on mobile and desktop, with no dependence on email filters
- LinkedIn InMail : for B2B, response rates three times higher than cold email
- Display retargeting : complement email with targeted ads on social networks and the web
Winning strategy: combine email, SMS and messaging apps in a single workflow. Email remains the backbone, but SMS takes over when email does not get through.
How WEVAL helps
At WEVAL Consulting, we support companies across the entire digital marketing value chain:
- Deliverability audit : an analysis of your infrastructure, reputation and compliance with the new ISP standards
- Multichannel strategy : defining the best mix of email, SMS and messaging for your audience and sector
- Technical integration : setting up authentication protocols and configuring sending and tracking tools
- Team training : deliverability best practices and reputation management
- Continuous monitoring : real-time dashboards and proactive alerts
Need to improve your deliverability and multichannel strategy?
Contact our experts