Most email problems don’t start with copy, targeting, or timing —
they start with infrastructure.
In 2024, Google and Yahoo rewrote the rules of corporate email delivery.
In 2025, enforcement is stricter than ever.
And for companies relying on outsourced outreach or third-party data, deliverability is not optional — it is the difference between:
80%+ inbox placement
70%+ of your emails silently routed to spam
In this guide, we break down the technical foundation that modern brands must implement to reach the inbox consistently — and explain how Pumpfiat builds this architecture into every client workflow.
1 Deliverability Isn’t Just Email — It’s Infrastructure
Most brands want better deliverability, but few understand the true cause of:
- low open rates
- spam filtering
- domain throttling
- blocklist risk
- inconsistent inboxing
These aren’t “marketing problems.”
They are reputation problems rooted in your technical setup.
The inbox wars of 2024–2025 made it clear:
Senders without authentication and reputation protection are treated as unsafe by default.
The result: your outreach never lands where it matters — even with great messaging.
2 The Three Authentication Pillars (SPF, DKIM, DMARC)
Deliverability starts with the core trio.
A. SPF — Proving Your Sending Sources
SPF tells mailbox providers which servers are allowed to send on your domain’s behalf.
Key rules:
- Include only approved vendors
- Remove deprecated sources
- Avoid “SPF flattening services”
- Maintain under 10-lookup limit
Pumpfiat always deploys strict SPF modes to prevent spoofing and shadow sends.
B. DKIM — Validating Message Integrity
DKIM cryptographically signs every outgoing email.
Prevents:
- content tampering
- domain impersonation
- phishing classification
Our DKIM keys use 2048-bit encryption — the modern security minimum.
C. DMARC — Enforcing Policy & Preventing Abuse
DMARC instructs ISPs how to treat unauthorized messages.
Stages:
- none (monitoring)
- quarantine (spam)
- reject (block)
For Pumpfiat, DMARC is standard — with reporting routed into automated analytics.
The authentication pipeline that protects your sender reputation
3 Google & Yahoo’s New Rules (2024 Update)
Both companies now enforce:
- Mandatory SPF, DKIM, DMARC
- One-click unsubscribe in the header
- Complaint rates < 0.3%
- Valid reverse DNS & matching HELO
- Enforced authentication alignment
- Clear sender identity
If any of these fail, your domain is treated as non-compliant — and inbox placement collapses.
This is why Pumpfiat builds layered authentication setups for every sending domain.
4 Domain Warm-Up Isn’t Optional Anymore
New domains have zero sending reputation.
Mailbox providers distrust them by default.
Warm-up is the process of:
- gradually increasing volume
- establishing trust
- spreading sending across time zones
- reducing complaints
- maximizing positive engagements
Pumpfiat uses AI-driven warm-up systems to:
- simulate natural engagement
- throttle based on mailbox-provider feedback
- measure hourly reputation changes
- adapt volume based on complaint signals
This replaces outdated static warm-up schedules.
From 0 to 50K sends — reputation-safe scaling
5 Infrastructure Segmentation: The New Deliverability Superpower
High-performing teams segment infrastructure into:
- Primary domain (brand)
- Subdomain for cold outreach
- Additional subdomains for testing & sequencing
- Unique routing for each region (US/EU/APAC)
- Dedicated IPs for high-volume lanes
- Rotating IP pools for outreach scalability
Why this matters:
One bad campaign shouldn't make your entire domain untrustworthy.
Pumpfiat deploys domain clusters so clients can scale outreach safely.
6 List Hygiene: The Quiet Destroyer of Deliverability
Poor hygiene is the #1 spam trigger.
This includes:
- unverified emails
- high-bounce segments
- inactive leads
- mismatched intent
- non-permissioned contacts
Pumpfiat solves this from the root:
- our database is permission-first
- all records include consent provenance
- multi-source verification removes duplicates
- bounce suppression is automatic
- opt-outs propagate globally
This keeps clients in compliance and preserves reputation.
7 Content Matters — But Not the Way You Think
Mailbox providers don’t care about pretty copy.
They care about:
- linguistic spam signals
- template repetition
- link density
- mismatched branding
- lack of address & identity
- misleading subject lines
- low-engagement patterns
Pumpfiat uses pre-send AI filtering to scan for spam-model triggers, reducing the chances of negative classification.
8 Deliverability Reporting: The Invisible Feedback Loop
You can’t optimize what you can’t measure.
Pumpfiat tracks:
- domain-level health
- IP reputation
- spam classification
- throttling
- complaint rates
- bounce distribution
- positive interactions
- regional inboxing variation
This is fed into machine-learning models that auto-correct sending behaviour before reputation drops.
9 The Pumpfiat Deliverability Framework
To summarize, our deliverability architecture includes:
- Authentication Setup
SPF, DKIM, DMARC, BIMI (optional), rDNS, alignment checks. - Infrastructure Segmentation
Subdomains, dedicated sends, multi-region routing. - Healthy Domain Warm-Up
AI-driven reputational scaling. - Intent-Aligned Audience Selection
Permission-first, verified, compliant contacts. - AI Spam-Model Prevention
Scanning every email before it goes out. - Complaint Management
Proactive suppression, feedback-loop ingestion. - Reputation Monitoring
Real-time tracking & machine-learning adjustment.
The outcome:
- Higher inbox placement
- Higher open rates
- Lower complaint risk
- Stronger brand reputation
- Sustainable, scalable outreach
10 Deliverability Isn’t Luck — It’s Engineering
The companies that win in 2025 are not the ones sending the most emails.
They’re the ones building the best infrastructure to protect their sender reputation.
Great emails don’t matter if no one sees them.
Deliverability is the foundation that makes everything else possible —
and that foundation starts with authentication, reputation, compliance, and intentional engineering.
This is the system Pumpfiat delivers for every client.