Raj Kapoor Litmus is the long-recognised leader in email pre-send testing: it lets marketing teams build an email, preview it across more than a hundred inbox clients, run a QA checklist, test against spam filters, and analyse performance after sending. In 2026 the story is as much about its pricing as its features — Litmus has moved … Read more
Mail-Tester is the free, no-signup web tool that grades a single test email out of ten and tells you, in plain language, what is hurting its chances of reaching the inbox. Send a message to the unique address it gives you, click a button, and you get a score plus a checklist of authentication, content … Read more
MXToolbox is the email diagnostics suite most administrators reach for first when something is wrong with mail. Need to know whether your sending IP is on a blacklist, whether your MX records resolve, or whether your SPF and DMARC are valid? MXToolbox answers all of that in seconds, for free. This MXToolbox review explains what … Read more
GlockApps is a deliverability-testing platform whose flagship feature sends your campaign to a list of real seed inboxes and reports exactly where it landed — inbox, spam, or the Gmail promotions tab. If you have ever hit send and wondered whether your subscribers actually saw the email, that uncertainty is the problem GlockApps exists to … Read more
Email authentication statistics 2026 (the headline numbers): across the top 10,000 domains, measured from live DNS in June 2026 — 84.5% publish SPF, 76.6% publish DMARC, but only 54.0% actually enforce DMARC (quarantine or reject). MTA-STS sits at 3.6%, TLS-RPT at 4.5%, and BIMI at 9.4%. The single biggest story is the DMARC enforcement gap: … Read more
Email API vs SMTP relay — which should you use? Use an email API (HTTP requests, webhooks, templating, event analytics) when you are writing application code and want speed and control. Use an SMTP relay when you are connecting an existing platform, plugin or tool that just expects SMTP credentials — the universal path of … Read more
The best email verification tools keep your list clean, your bounce rate low and your sender reputation healthy — but “verification” is really a family of jobs, from validating addresses to testing inbox placement to checking your DNS. This guide compares the leading email verification and testing tools of 2026 and, because they are complementary … Read more
NeverBounce is a popular email verification service for cleaning lists of invalid addresses, with a strong real-time API and an automated CRM-cleaning option. Owned by the Mailchimp ecosystem, it is known for accurate bulk verification at a competitive per-address price. This NeverBounce review covers NeverBounce pricing in 2026, accuracy, the features that stand out, and … Read more
ZeroBounce is a premium email verification service that cleans your list of invalid, risky and spam-trap addresses before you send — and bundles a wider deliverability suite around it. Keeping a clean list is one of the highest-leverage things you can do for inbox placement, and ZeroBounce is one of the most accurate and feature-rich … Read more
Is email encrypted in transit? Usually yes — modern mail travels between servers over TLS. But two caveats matter: standard TLS is opportunistic, so an attacker can silently strip it and force the message into plain text, and even when TLS holds, the servers at each end can still read the content. To make transit … Read more