Since Nov 5, Hotmail and Outlook.com bounce small senders with 550 5.7.1 and Microsoft never announced it. The dig checks and DNS records that fix it.
AI agents sending email often land in spam. Here's how to fix SPF, DKIM, and DMARC issues and build reliable programmatic email delivery.
A step-by-step guide to self-hosting your own email server with Mailcow, DNS configuration, deliverability debugging, and maintenance tips.
Self-hosted email keeps getting rejected? Here's why IP reputation matters more than perfect DNS records, and how to maximize deliverability.
