
Mailjet: Complete Technical Guide for Transactional Email in 2026
A comprehensive guide for developers and system admins: DKIM configuration, API v3 vs v3.1, dedicated vs shared IP, and pitfalls to avoid with Mailjet.

A comprehensive guide for developers and system admins: DKIM configuration, API v3 vs v3.1, dedicated vs shared IP, and pitfalls to avoid with Mailjet.

A detailed technical guide for developers: DNS configuration (SPF, 2048-bit DKIM), Web API v3, SMTP Relay, dedicated vs shared IP, limits and webhooks.

A comprehensive guide for developers and sysadmins: DKIM configuration, choosing between API and SMTP, technical limits, and pitfalls to avoid with Brevo.

A comprehensive guide to compare the best public DNS resolvers: privacy, security, family filtering, DoH/DoT/DoQ, and deployment methods.

Surfshark DNS is a free public DNS resolver (IPv4/IPv6, DoH) focused on privacy. Here's when to use it, how to configure it, and what to check.

DNS4EU is a European public DNS with 5 variants (security, kids, ad blocking, neutral) and IPv4/IPv6 + DoH/DoT addresses. Deployment and verification guide.

CleanBrowsing is a public filtering DNS resolver (Family/Adult/Security) with DoH/DoT. Practical guide: router, mobile, checks, and anti-bypass.

NextDNS is a customizable DNS resolver: DoH/DoT encryption, filtering, profiles, and logs. Here’s how to deploy it cleanly at home or in an SMB.

AdGuard DNS is a public DNS resolver that can block ads/trackers (and, in Family mode, adult content). Addresses, DoH/DoT/DoQ, and an action plan.
DNS Lookup
Choose a DNS record type to search for.
Propagation & diagnostics
Compare resolvers worldwide and inspect returned answers.
Keep history, monitor your zones and automate recurring checks.
Email authentication
Tools to verify and validate your email authentication setup.
Deliverability
Email deliverability audit
Audit MX, SPF, DKIM and DMARC to confirm a domain is ready to send.
Mail header analyzer
Decode participants, authentication results and routing from raw headers.
Email tester
Send a test email and get instant authentication and deliverability feedback.
IP Blacklist Checker
Check if your IP is on email blacklists
Domain Blacklist Checker
Check if your domain is on URI blacklists
SPF Flattener
Flatten SPF records to reduce DNS lookups below the 10-lookup limit.
DKIM Selector Finder
Auto-discover all DKIM selectors for a domain via DNS brute-force.
Text
Transform, encode and measure your content in seconds.
Text case converter
Convert any block of text to upper or lower case instantly.
Base64 encoder / decoder
Encode or decode any content in Base64 without leaving the browser.
Slug generator
Transform any sentence into an SEO-friendly slug in seconds.
Word & character counter
Measure the length of any text, with instant word and character counts.
Web & Certificates
BIMI logos, VMC/CSR certificates and web page diagnostics.
BIMI logo lookup
Inspect a BIMI logo URL - format, metadata and live rendering - before rollout.
CSR parser
Inspect a CSR, extract subject details, fingerprints and requested SANs.
VMC inspector
Inspect a Verified Mark Certificate - issuer, validity and SAN coverage - before you publish BIMI.
Page size checker
Check if your page exceeds Google's 2 MB crawl limit.
IP
Look up addresses, owners, reverse records and ranges.