Blog
Guides on email deliverability, DNS configuration, and mail server operations
Welcome to the InboxTooling Blog
Introducing the InboxTooling blog — your resource for email deliverability guides, DNS best practices, and mail server operations.
Is Your Website Blacklisted? How to Check and Recover
Learn how to check if your website is blacklisted by Google Safe Browsing, antivirus vendors, or spam databases, and follow step-by-step recovery instructions.
What Is SMTP Relay and How Does It Work? | InboxTooling
Understand SMTP relay: how mail transfer agents chain together, open relay risks, authenticated relay, smart hosts, and relay services. Covers RFC 5321.
Email Spam Scores Explained: How SpamAssassin Scoring Works and How to Improve
Understand how email spam scores are calculated, what triggers high scores in SpamAssassin and other filters, and how to test and fix deliverability issues.
Domain Ownership Explained: What You Need to Know | InboxTooling
Understand how domain ownership works: registration, WHOIS records, renewal, transfer, and the rights and responsibilities that come with owning a domain name.
SSL Certificates Explained: Types, Installation & Troubleshooting | InboxTooling
Complete guide to SSL certificates covering DV, OV, and EV types, Let's Encrypt setup, certificate chains, auto-renewal, common errors, and HTTPS migration.
SPF, DKIM & DMARC Explained: Complete Setup Guide for Email Authentication
Learn how SPF, DKIM, and DMARC work together to protect your domain from spoofing and improve deliverability. Step-by-step setup instructions and common mistakes to avoid.
How to Delay or Schedule an Email in Outlook | InboxTooling
Learn how to delay sending emails in Outlook using rules, schedule emails for a specific time, and configure delayed delivery in Desktop, Web, and New Outlook.
Microsoft 365 SMTP Settings: Configure Email Sending | InboxTooling
Complete Microsoft 365 SMTP configuration guide. Covers client submission, SMTP relay, direct send, connector setup, and authentication for smtp.office365.com.
How to Whitelist Emails So They Never Go to Spam | InboxTooling
Step-by-step guide to whitelisting emails in Gmail, Outlook, Yahoo, and Apple Mail. Prevent important messages from landing in spam with filters and safe sender lists.