The Deliverable Diary

DMARC is a small text record you publish in your domain’s DNS that tells receiving mail servers what to do if a message claiming to be from your domain fails SPF or DKIM checks. It does three things: it authenticates your outbound mail, it tells receivers how to handle failures (ignore, junk, or reject), and […]

You can have everything else in place – domain authenticated (SPF, DKIM, DMARC), a clean, opt-in mailing list, solid content – but still end up in spam. Why? Because deliverability isn’t just technical. It’s behavioral. The hidden influence behind inbox placement Mailbox providers such as Gmail and Outlook don’t just look at what you send. […]

With the explosion of messaging apps, collaboration platforms and social media, it’s easy to assume email is losing ground. When it comes to reliable communication, instant tools such as Slack, WhatsApp and Microsoft Teams promise faster, more immediate messaging – and in many cases, they deliver. But, speed isn’t the same as reliability. For businesses […]

You hit send. The recipient never gets it. Back comes a wall of text with something like 550 5.7.26 buried in it. This page tells you what every code means and what to actually do about it. Bookmark it. Key takeaways 4xx means temporary. Retry, then look closer if it persists. 5xx means permanent for […]

To send a correction email or not? We’ve all been there… You’ve spent hours crafting the perfect email: proofreading every word, testing every link and hitting send with TOTAL CONFIDENCE! But then, horror of horrors, you realize you’ve made a blunder. Maybe you’ve misspelt someone’s name, sent the wrong offer, or included a broken link. […]

Short version. If you’re not Amazon, not running your own postmaster team, and your inbox placement matters to your customers, SMTP2GO is the safest default. The 5 picks in 60 seconds If you don’t have time for the full piece, here’s the shortlist. Pick Best for Free plan Starts at Tested deliverability (2026) 1. SMTP2GO […]