How We Test Email Marketing Platforms

By Alaa, Founder of SMTPedia.

What we test

For each platform we review, we run a testing session of 60 to 90 minutes minimum covering eight areas :

1. Signup and onboarding : we create a real account (free trial or lowest paid tier), configure sender authentication (SPF, DKIM, DMARC), and note the friction of the first-time setup.
2. Contact list import : we upload a 100-subscriber CSV seed list, verify field mapping, deduplication behavior, and suppression handling.
3. Campaign builder : we build one broadcast campaign end-to-end using the default template library, test drag-and-drop editing, personalization tags, and preview modes.
4. Automation editor : we build a two-step welcome workflow (trigger on subscribe, send email 1, wait 24h, send email 2), test conditional splits when available.
5. Reports and analytics : we send the campaign to our seed list, wait 48 hours, then explore the campaign report interface. We note what metrics are available, whether we can export raw data, and how granular the reporting is.
6. Sender authentication and infrastructure : we verify DKIM/SPF/DMARC alignment via mxtoolbox.com and our own auth checker, note whether the platform uses shared or dedicated IPs, and check for BIMI support.
7. API, SMTP, and MCP : if the platform exposes an API, we generate credentials, read the docs, and test one authenticated request (typically send transactional). We check if an official MCP endpoint exists.
8. Third-party deliverability test : we send our test campaign to a GlockApps seed list of 60+ inboxes covering major providers (Gmail, Yahoo, Outlook, iCloud, and B2B servers), then record the inbox placement report 24 hours later.

The six categories we rate

Every ESP is scored 1 to 10 across six categories, weighted equally in the overall rating :

The overall rating is the weighted average of these six scores. We do not run user-submitted ratings on our reviews : expert scores only. This is a deliberate choice to keep review scoring consistent and free from vendor-orchestrated review campaigns.

Third-party ratings we aggregate

We complement our own hands-on scores with third-party aggregated ratings from three sources :

• G2 : product satisfaction score (0-5) + number of verified reviews
• Capterra : overall rating (0-5) + review count
• TrustPilot : TrustScore (0-5) + review volume

These are fetched at the time of publication and refreshed on each review update (quarterly for top 10 platforms, annually for the rest). Each third-party rating shows the source, the score, the review count, and the fetch date so you can verify freshness.

Screenshots and evidence

Every review includes at least six dated screenshots taken during our testing session :

1. Signup flow (final onboarding screen)
2. Dashboard (post-login home)
3. Campaign builder (mid-edit state)
4. Automation editor (workflow overview)
5. Campaign report (post-send)
6. Sender authentication settings

Screenshots are captured at the time of testing, dated, and stored in the WordPress Media Library with the naming convention {platform}-{tab}-{n}.webp. If a platform’s UI changes materially after a review is published, we re-test and refresh the screenshots (see refresh cadence below).

Refresh cadence

An ESP review is a living document. We follow this refresh policy :

Every review carries a Last tested: {date} badge visible above the fold. If you see a date older than 12 months on a review, we welcome you to flag it via the contact form and we will re-prioritize it.

What makes an ESP get a bad score

We publish critical reviews. If a platform underperforms on our tests, the review reflects it. Common reasons a platform receives a low rating :

• Poor deliverability : inbox placement below 85% in our GlockApps test
• Hidden fees : overage costs, sunset fees, or plan gotchas not disclosed on the pricing page
• Broken sender authentication : DKIM misalignment, no DMARC guidance, shared IPs with visible reputation issues
• Dark patterns : automatic upgrades, difficult cancellation flows, opt-out gymnastics for basic features
• Support failure : tickets unanswered after 5 business days, or unhelpful canned responses
• API decay : outdated documentation, breaking changes without notice, or missing rate limit headers

We name these problems plainly. We do not hedge to protect affiliate relationships.

Our affiliate disclosure

Many of the platforms we review offer affiliate programs. We participate in some of these programs, and receive commissions when readers sign up for a platform through our links. This does not influence our ratings or our verdicts.

Concrete safeguards we operate :

• Editorial independence : ratings are set before any affiliate consideration, based on the testing session outcomes only.
• Non-affiliate platforms : we review platforms with no affiliate program (Amazon SES, self-hosted tools like Mautic, some enterprise ESPs). We rate them on the same 6-category scale.
• Bad scores for affiliate partners : if an affiliate partner scores poorly, we publish the poor score. We do not remove them from our comparison hubs to protect commission.
• Disclosure per page : every review that contains affiliate links carries a visible disclosure banner in the footer.

Full disclosure policy : Editorial Independence and Affiliate Disclosure.

Who we are

Alaa Touil · Founder of SMTPedia · 8+ years in email infrastructure, deliverability, and SMTP operations. Reviews conducted by Alaa.

Rabeb Guitni · Editorial reviewer · Proofreads and fact-checks every review before publication.

Every review is written by Alaa based on a testing session Alaa conducted personally. Rabeb reviews the draft for factual accuracy, tone consistency, and completeness before publication. Both bylines appear on every review with photos and links to their author pages.

Corrections and factual disputes

If you find a factual error in one of our reviews (wrong pricing, outdated screenshot, mis-attributed feature), please email us at contact@smtpedia.com. We aim to acknowledge within 48 hours and correct within 5 business days if the claim is substantiated.

If you are a vendor and disagree with our assessment, you can also reach out via the same address. We will not remove a review or change a rating in exchange for advertising or affiliate deals, but we will publish factual corrections and re-test if new information warrants it.

Why we test this way

Existing ESP comparison sites (we will not name them here) rely heavily on vendor documentation, G2 aggregation, and paraphrased marketing pages. This produces reviews that are directionally right on features but weak on real-world performance signals like deliverability, support quality, and hidden costs.

SMTPedia is built on a technical foundation : 500+ SMTP configuration guides, a comparison tool used by 400+ platforms, and an ADN focused on deliverability, not marketing. Our reviews inherit that positioning. We test because we can, and we test because email decisions are expensive to reverse. A wrong ESP choice can cost a business months of migration work and thousands of dollars in lost sender reputation.

If you find our reviews useful, the best way to support us is to sign up through our affiliate links when you decide on a platform. If you find an error or want to challenge a verdict, our inbox is open.

Related :

• Editorial Independence and Affiliate Disclosure
• Browse all reviews
• About SMTPedia