Deliverability & DNS

SPF Fail: Decode the Error and Fix It Fast

Your email bounced with 550 5.7.1 or 5.7.26 and a client is waiting. An SPF fail is a DNS authentication failure, not a content problem. This guide decodes the error, finds the failing IP in your headers, and walks through the three fixes that resolve most cases.

Apr 1, 2026 · Alexey Bulygin

Improve Email Deliverability: 30-Minute Checklist

Your mail can get a 250 OK and still vanish. This 30-minute checklist shows how to improve email deliverability by fixing SPF, DKIM, DMARC, reverse DNS, and complaint rate before you waste time on the wrong thing.

Mar 31, 2026 · Alexey Bulygin

Email Deliverability Monitoring: The 15-Minute Routine

Your SMTP server says 250 OK. Your client never saw the email. That silence is what makes email deliverability monitoring critical — and neglected. Here's the free-tool routine that catches failures before they torch your domain.

Mar 30, 2026 · Alexey Bulygin

Email List Verification: How to Clean Your List Before It Kills Your Deliverability

Bad email addresses destroy sender reputation silently. Every bounce, spam trap hit, and invalid address chips away at your domain score until real messages start landing in spam. Here is how email list verification works, what it actually checks, and how to clean your list before your next send.

Mar 24, 2026 · Alexey Bulygin

Create SPF Record Without Hitting the 10-Lookup Limit

Most SPF guides tell you what to paste. This one shows how to build an SPF layout that survives vendor sprawl, lookup limits, and future DNS changes.

Mar 21, 2026 · Alexey Bulygin

How TrekMail Protects Your Inbox

Your TrekMail inbox is protected by automatic spam filtering, phishing detection, and attachment scanning — all running locally on our servers. Here is what that means for you.

Mar 21, 2026 · Alexey Bulygin

SPF Record Setup: Step-by-Step Guide With Provider Examples

SPF isn't optional. Since February 2024, Google and Yahoo reject mail from domains without it. This guide covers the complete SPF record setup — syntax, provider configs, DNS publishing, and CLI validation — so you get it right the first time.

Mar 18, 2026 · Alexey Bulygin

SPF Record for Email: Exact Setup for Business Domains

Your SPF record for email is either right or it isnt. Since February 2024, Google and Yahoo reject messages from domains with broken or missing SPF. Heres the exact configuration for your setup, plus the hidden traps that make correct-looking records fail silently.

Mar 18, 2026 · Alexey Bulygin

Email Sender Reputation: 4 Signals That Matter

Mailbox providers score your email sender reputation on four specific signals. Understand the complaint rate cliff, authentication requirements, volume thresholds, and IP hygiene rules — then fix them before your mail stops delivering.

Mar 17, 2026 · Alexey Bulygin

Email Domain Reputation: Why It Tanks & How to Fix It

Your email domain reputation has been degrading quietly — by the time you notice, you're already muted. Four specific causes kill it. Here's the diagnostic workflow and structured recovery protocol.

Mar 16, 2026 · Alexey Bulygin

Domain Reputation Email: Why Your Domain Gets Tainted

Your emails keep landing in spam, even after switching hosts and getting a fresh IP. The problem isn't your server — it's your domain name. Domain reputation email damage follows the domain. Here's how to diagnose it, prevent it, and recover.

Mar 16, 2026 · Alexey Bulygin

Domain Reputation: Build, Drop, and Recover | TrekMail

Your domain has a reputation score with every major inbox provider. Cross 0.3% spam complaints and you're blocked. Here's how domain reputation works, what destroys it, and the exact recovery protocol.

Mar 15, 2026 · Alexey Bulygin