Deliverability
Fix: SPF PermError: too many DNS lookups
What "SPF PermError: too many DNS lookups" means and exactly how to fix it — with the DNS or client change that resolves it for good.
July 5, 2026
Deliverability
Fix: 550 5.7.1 message rejected due to SPF
What "550 5.7.1 message rejected due to SPF" means and exactly how to fix it — with the DNS or client change that resolves it for good.
July 5, 2026
Deliverability
Fix: DKIM signature did not verify
What "DKIM signature did not verify" means and exactly how to fix it — with the DNS or client change that resolves it for good. Practical guide for…
July 5, 2026
Deliverability
Fix: DMARC fail / message rejected by DMARC policy
What "DMARC fail / message rejected by DMARC policy" means and exactly how to fix it — with the DNS or client change that resolves it for good.
July 5, 2026
Deliverability
Fix: 421 4.7.0 temporarily rate limited
What "421 4.7.0 temporarily rate limited" means and exactly how to fix it — with the DNS or client change that resolves it for good.
July 5, 2026
Deliverability
Fix: 550 5.1.1 user unknown / recipient rejected
What "550 5.1.1 user unknown / recipient rejected" means and exactly how to fix it — with the DNS or client change that resolves it for good.
July 5, 2026
Deliverability
Fix: my email goes to spam in Gmail
What "my email goes to spam in Gmail" means and exactly how to fix it — with the DNS or client change that resolves it for good. Practical guide for…
July 5, 2026
Deliverability
Fix: Google & Yahoo bulk sender requirements
What "Google & Yahoo bulk sender requirements" means and exactly how to fix it — with the DNS or client change that resolves it for good.
July 5, 2026
Deliverability
Fix: 454 4.7.0 cannot authenticate / SMTP auth failed
What "454 4.7.0 cannot authenticate / SMTP auth failed" means and exactly how to fix it — with the DNS or client change that resolves it for good.
July 5, 2026
Deliverability
Fix: connection timed out on port 25
What "connection timed out on port 25" means and exactly how to fix it — with the DNS or client change that resolves it for good. Practical guide for…
July 5, 2026
Deliverability
Fix: MX record not found / no mail server for domain
What "MX record not found / no mail server for domain" means and exactly how to fix it — with the DNS or client change that resolves it for good.
July 5, 2026
Deliverability
Fix: soft bounce vs hard bounce — what to do
What "soft bounce vs hard bounce — what to do" means and exactly how to fix it — with the DNS or client change that resolves it for good.
July 5, 2026
Deliverability
Fix: SPF: none (no SPF record found)
What "SPF: none (no SPF record found)" means and exactly how to fix it — with the DNS or client change that resolves it for good. Practical guide for…
July 5, 2026
Deliverability
Fix: no DMARC record / DMARC: none
What "no DMARC record / DMARC: none" means and exactly how to fix it — with the DNS or client change that resolves it for good. Practical guide for…
July 5, 2026
Deliverability
Fix: reverse DNS / PTR does not match
What "reverse DNS / PTR does not match" means and exactly how to fix it — with the DNS or client change that resolves it for good.
July 5, 2026
Deliverability
Fix: email delayed by greylisting
What "email delayed by greylisting" means and exactly how to fix it — with the DNS or client change that resolves it for good. Practical guide for…
July 5, 2026
Deliverability
Fix: too many recipients / 452 4.5.3
What "too many recipients / 452 4.5.3" means and exactly how to fix it — with the DNS or client change that resolves it for good. Practical guide for…
July 5, 2026
Deliverability
Fix: my domain or IP is blacklisted
What "my domain or IP is blacklisted" means and exactly how to fix it — with the DNS or client change that resolves it for good. Practical guide for…
July 5, 2026
Deliverability
Fix: SPF vs DKIM vs DMARC explained
What "SPF vs DKIM vs DMARC explained" means and exactly how to fix it — with the DNS or client change that resolves it for good. Practical guide for…
July 5, 2026
Deliverability
Fix: From address looks like spoofing / via warning
What "From address looks like spoofing / via warning" means and exactly how to fix it — with the DNS or client change that resolves it for good.
July 5, 2026
Deliverability
Fix: should I use a catch-all address
What "should I use a catch-all address" means and exactly how to fix it — with the DNS or client change that resolves it for good.
July 5, 2026
Deliverability
Fix: not receiving any email on my domain
What "not receiving any email on my domain" means and exactly how to fix it — with the DNS or client change that resolves it for good.
July 5, 2026
Deliverability
Fix: attachment too large / message size exceeds limit
What "attachment too large / message size exceeds limit" means and exactly how to fix it — with the DNS or client change that resolves it for good.
July 5, 2026
Deliverability
Fix: SSL certificate error connecting to mail server
What "SSL certificate error connecting to mail server" means and exactly how to fix it — with the DNS or client change that resolves it for good.
July 5, 2026
Deliverability
Fix: how long until my email DNS records work
What "how long until my email DNS records work" means and exactly how to fix it — with the DNS or client change that resolves it for good.
July 5, 2026
Deliverability
Fix: more than one SPF record found
What "more than one SPF record found" means and exactly how to fix it — with the DNS or client change that resolves it for good. Practical guide for…
July 5, 2026
Deliverability
Fix: should I send from a no-reply address
What "should I send from a no-reply address" means and exactly how to fix it — with the DNS or client change that resolves it for good.
July 5, 2026
Deliverability
Fix: Gmail shows a red question mark on my sender
What "Gmail shows a red question mark on my sender" means and exactly how to fix it — with the DNS or client change that resolves it for good.
July 5, 2026
Deliverability
Fix: 552 mailbox full / over quota
What "552 mailbox full / over quota" means and exactly how to fix it — with the DNS or client change that resolves it for good. Practical guide for…
July 5, 2026
Deliverability
Fix: STARTTLS not supported / must issue STARTTLS first
What "STARTTLS not supported / must issue STARTTLS first" means and exactly how to fix it — with the DNS or client change that resolves it for good.
July 5, 2026
Deliverability
Fix: email still delivering to my old provider
What "email still delivering to my old provider" means and exactly how to fix it — with the DNS or client change that resolves it for good.
July 5, 2026
Deliverability
Fix: OquMail domain verification stuck on pending
What "OquMail domain verification stuck on pending" means and exactly how to fix it — with the DNS or client change that resolves it for good.
July 5, 2026
Deliverability
GDPR and Business Email Hosting: What EU Startups Should Know
Data processing, subprocessors, and practical steps for GDPR-conscious teams choosing email hosting for @yourcompany.eu domains. Practical guide for…
June 16, 2026
Deliverability
Why Your Business Emails Land in Promotions (Not Inbox)
Gmail tabs, engagement signals, and authentication — fixes for legitimate senders. Practical guide for non-technical small business owners.
June 16, 2026
Deliverability
Spam Complaint Rate Explained for Small Senders
What counts as a complaint, acceptable thresholds, and how one bad list hurts everyone on your domain. Learn spam complaint rate in plain language.
June 16, 2026
Deliverability
Soft Bounce vs Hard Bounce: What to Do With Each
Temporary failures vs permanent — how to read SMTP codes and clean your lists. Learn soft bounce hard bounce in plain language. Practical guide for…
June 16, 2026
Deliverability
Email Reputation for New Domains: A Realistic Timeline
Week one to month three — what to expect when your domain has no sending history. Learn new domain email reputation in plain language.
June 16, 2026
Deliverability
How to Read DMARC Aggregate Reports (RUA)
XML reports demystified — who sends as your domain and whether authentication passes. Learn DMARC reports explained in plain language.
June 16, 2026
Deliverability
How Small Businesses Avoid the Spam Folder
Authentication, content, lists, and volume — practical deliverability without an ESP enterprise contract. Learn avoid spam folder business email in plain language.
June 16, 2026
Deliverability
Reply-To Address Best Practices for Business & API Mail
Why noreply@ hurts deliverability and what to use instead for transactional messages. Learn reply-to address best practices in plain language.
June 16, 2026
Deliverability
SPF, DKIM & DMARC Failures Explained (Fix Guide for Founders)
What authentication failures mean in headers, common misconfigurations, and copy-paste fixes for small business domains. Learn SPF failure in plain language.
June 15, 2026
Deliverability
Catch-All Email: Why It Hurts Deliverability (and What to Do Instead)
Catch-all addresses collect spam and hide bounces. Learn safer patterns for startups that want every name@ to work. Practical guide for non-technical small…
June 15, 2026
Deliverability
Email Blacklist Check: What to Do If Your Domain Gets Listed
DNSBLs, spamhaus listings, and remediation steps for small businesses — prevention via authentication and hygiene. Learn email blacklist check in plain language.
June 14, 2026
Deliverability
Email Domain Warmup: New Domain Reputation for Business Mail
Sending volume ramps, authentication checks, and mistakes that burn a fresh domain — for startups sending their first real campaigns. Learn email domain…
June 13, 2026
Deliverability
Transactional Email vs Marketing Email: Different Rules, Different Risk
Receipts, password resets, and newsletters are not the same — authentication, volume patterns, and why to separate them. Learn transactional vs marketing…
May 26, 2026
Deliverability
Bounce Rate and Sender Reputation: What Small Businesses Should Track
Hard vs soft bounces, complaint rates, and how OquMail's deliverability dashboard helps you spot problems early. Practical guide for non-technical small…
May 17, 2026
Deliverability
The Small Business Email Deliverability Checklist (Printable)
Fifteen checks before you send marketing or transactional mail — DNS, content, lists, monitoring, and bounce handling. Learn email deliverability checklist…
May 11, 2026
Deliverability
Why Your Business Emails Go to Spam (And How to Fix It)
Authentication failures, reputation, content signals, and list hygiene — a practical checklist to get back to the inbox. Learn emails going to spam in plain…
May 4, 2026