The Complete Email Deliverability Guide: Setting Up SPF, DKIM, and DMARC in Brevo & Campaigner

If you run an e-commerce store, a marketing agency, or a B2B SaaS platform, email is likely your highest-converting revenue channel. However, crafting the perfect subject line and designing a stunning template means absolutely nothing if your emails are quietly routed to the spam folder or permanently rejected by receiving servers.

Deliverability is no longer a dark art left to IT departments; it is a critical marketing function. With Google and Yahoo enforcing strict, non-negotiable authentication requirements for bulk senders, compliance is the only way into the primary inbox. Failing to configure your domain’s cryptographic keys and alignment policies correctly guarantees your campaigns will fail.

This comprehensive, highly technical guide explains exactly how to achieve 100% compliance with modern inbox providers by configuring SPF, DKIM, and DMARC. We will explore the precise step-by-step setup processes for two leading marketing platforms—Brevo and Campaigner—and evaluate how their underlying infrastructure impacts your long-term deliverability and software ROI.

1. Executive Summary & Quick Verdict

The Verdict: Both Brevo and Campaigner offer robust deliverability tools necessary to satisfy Google and Yahoo’s strict bulk sender requirements.

For the vast majority of small-to-medium businesses (SMBs), scaling e-commerce brands, and developers, Brevo is the superior choice. Brevo provides automated domain delegation, a dedicated transactional SMTP engine, and a highly lucrative volume-based pricing model. Alternatively, Campaigner serves as a premium, enterprise-grade solution that offers deep data handling and high-volume delivery, though it requires a slightly more manual setup process and utilizes an expensive, contact-based pricing model.

2026 Deliverability Scorecard

• Ease of Setup: Brevo 4.8 / 5 | Campaigner 3.9 / 5
• Authentication Depth: Brevo 4.9 / 5 | Campaigner 4.8 / 5
• Pricing & Value: Brevo 5.0 / 5 | Campaigner 3.5 / 5
• Overall Score: Brevo 4.9 / 5 | Campaigner 4.0 / 5

2. Understanding the Deliverability Trinity: SPF, DKIM, and DMARC

When an email arrives at a receiving mailbox provider like Gmail or Outlook, a sequence of automated checks occurs before the message is allowed into the inbox. These checks rely on three independent but interconnected DNS records: SPF, DKIM, and DMARC.

• SPF (Sender Policy Framework): This DNS record acts as a public guest list. It lists every IP address and server that is explicitly authorized to send mail on behalf of your domain. The receiver compares the IP of the incoming message to this list. SPF checks where the email came from to ensure it was dispatched by an authorized sending server.
• DKIM (DomainKeys Identified Mail): This protocol adds a digital, cryptographic signature to every outgoing email. By checking this signature against a public key stored in your DNS, receiving servers can confirm that the email’s content and headers were not tampered with or modified while in transit. DKIM effectively checks message integrity.
• DMARC (Domain-based Message Authentication, Reporting, and Conformance): DMARC acts as the ultimate enforcer. It tells receiving servers exactly what to do if an incoming email fails the SPF or DKIM checks. DMARC checks who sent the email by evaluating the sender identity in the “From” field and ensures it aligns with the authenticated domains.

The New Rules: Meeting Google & Yahoo Bulk Sender Requirements

In February 2024, Google and Yahoo fundamentally changed the email marketing landscape by introducing mandatory requirements for bulk senders (defined as sending 5,000+ emails per day). To avoid permanent 550 rejection errors, you must strictly adhere to the following rules:

1. Full Authentication: You are required to have valid SPF, DKIM, and DMARC records published in your domain’s DNS.
2. One-Click Unsubscribe: Your emails must include a functional one-click unsubscribe header (RFC 8058).
3. Spam Complaint Thresholds: Your user-reported spam complaint rate must stay below 0.3% at all times.

3. How to Set Up Email Authentication in Brevo

Brevo (formerly Sendinblue) provides two distinct pathways for domain authentication: individual DNS records or a fully automated “Brevo-managed setup” using Nameserver (NS) delegation.

For maximum deliverability, Brevo highly recommends setting up a branded subdomain (e.g., emails.yourcompany.com). A branded subdomain replaces Brevo’s default tracking URLs (like img.brevolinks.com) with your own domain, maintaining consistent brand visibility. More importantly, it enables full SPF alignment on your sending domain, which strengthens your DMARC posture and shields your root domain from potential deliverability issues.

Step-by-Step Brevo Implementation

1. Add Your Sending Domain:
   • In the Brevo dashboard, click the account dropdown and navigate to Settings > Senders, Domains, IPs > Domains.
   • Click Add a domain and enter your desired sending domain (e.g., yourcompany.com or emails.yourcompany.com) without the https:// or www prefixes.
2. Configure SPF (Sender Policy Framework):
   • If you opt for manual, individual DNS configuration, you must add Brevo’s IP space to your domain’s SPF record.
   • Create or edit a TXT record at the root of your sending domain with the following value: v=spf1 include:spf.brevo.com ~all.
   • If you choose the Brevo-managed setup via a branded subdomain, Brevo will host and manage the SPF record on your behalf.
3. Configure DKIM (DomainKeys Identified Mail):
   • Brevo achieves DMARC compliance via DKIM by generating custom DKIM signatures.
   • If you use NS delegation for a branded subdomain, Brevo automatically hosts the required DKIM record. If configuring manually, Brevo will provide a specific TXT record containing your public key that you must paste into your DNS provider (e.g., Cloudflare, GoDaddy).
4. Configure DMARC:
   • Create a TXT record with the host name _dmarc.
   • Brevo provides a placeholder DMARC record, but you must ensure it includes a reporting tag. Brevo asks you to append its specific rua tag to your DMARC value: ; rua=mailto:rua@dmarc.brevo.com.
   • A completed, monitoring-mode DMARC record for Brevo will look like this: v=DMARC1; p=none; rua=mailto:rua@dmarc.brevo.com.
5. Verify Authentication:
   • Return to Brevo and click Authenticate this email domain. Green checkmarks will appear once the DNS propagation is successful.

4. How to Set Up Email Authentication in Campaigner

Campaigner operates as a traditional enterprise MTA, requiring a slightly more manual DNS configuration process. Campaigner explicitly monitors authentication checks and requires proper setup to prevent spoofing and blocking.

Step-by-Step Campaigner Implementation

1. Configure SPF:
   • Login to your DNS management console and edit your existing SPF TXT record.
   • You must include Campaigner’s outbound email network. Add the following include mechanism: include:_spf.emailcampaigns.net.
   • Your final TXT record should look like this: v=spf1 include:_spf.emailcampaigns.net ~all.
   • Note on Alignment: By default, Campaigner sets you up to send using one of their domains for the Return-Path address, which means the message will not pass strict SPF alignment. Therefore, setting up DKIM is absolutely mandatory to ensure DMARC compliance.
2. Configure DKIM:
   • Campaigner requires you to set up DKIM using a CNAME record.
   • Create a CNAME record with the host em._domainkey (or em._domainkey.yourdomain.com) and point it to the value: dkim.emailcampaigns.net.
3. Configure DMARC:
   • To use DMARC with Campaigner, you must first configure your DKIM domain successfully.
   • Create a TXT record for _dmarc.yourdomain.com.
   • Start with a monitoring policy: v=DMARC1; p=none; rua=mailto:your-email@yourdomain.com. Once Campaigner detects that DMARC and DKIM are fully configured on your end, they will validate the services on their sending servers.
   • After monitoring reports to ensure legitimate mail is passing, gradually shift your DMARC policy from p=none to p=quarantine, and finally to p=reject.

5. Platform Comparison: The Pricing and Multi-Channel Advantage

While both Brevo and Campaigner offer robust infrastructure for achieving high deliverability and DMARC alignment, their pricing models and platform ecosystems are vastly different.

The Contact Tax vs. Volume-Based Pricing

Legacy email platforms, including Campaigner, Mailchimp, and ActiveCampaign, rely on a contact-based pricing model. This means you are billed a monthly subscription fee based on the total number of contacts stored in your database. As your business successfully acquires new leads, your software costs skyrocket, penalizing you for list growth.

Brevo completely disrupts this outdated model. Brevo offers unlimited contact storage across all of its pricing tiers—including the Free plan. Instead of taxing your audience size, Brevo charges based exclusively on the volume of emails you send per month.

For e-commerce operators and B2B businesses with large lead lists who only send campaigns a few times a month, Brevo offers spectacular ROI.

Multi-Channel Capabilities and Built-In CRM

Email deliverability is only one pillar of modern marketing. To maximize revenue, brands must reach customers where they are most active.

• Campaigner focuses almost exclusively on enterprise email execution and complex multivariate testing. It lacks native omnichannel messaging, meaning you must integrate separate third-party software for SMS or chat.
• Brevo acts as a unified omni-channel platform. It allows marketers to orchestrate automated workflows that branch seamlessly between Email, native SMS marketing, and the official WhatsApp Business API. Furthermore, Brevo includes a built-in Sales CRM for visual deal tracking and pipeline management, consolidating multiple expensive software subscriptions into a single, affordable interface.

6. Final Recommendation & Call to Action

In an era where Google and Yahoo enforce zero-tolerance policies for unauthenticated bulk mail, hoping for inbox placement is a losing strategy. You must proactively secure your domain using SPF, DKIM, and strict DMARC policies.

While Campaigner is a powerful enterprise tool capable of satisfying complex delivery requirements, its contact-based pricing and lack of native multi-channel tools make it an expensive choice for most scaling businesses.

Brevo emerges as the definitive solution for developers, e-commerce stores, and marketing agencies. By providing an automated approach to DKIM and SPF alignment via branded subdomains, a dedicated transactional email engine, and a volume-based pricing model that includes unlimited contacts, Brevo ensures your emails land in the primary inbox without inflating your monthly software budget.

Ready to secure your domain deliverability and stop paying a contact tax?