How to check spam score pre-send (e.g., Mail-Tester, Glock)?

Pre-send spam testing services let you evaluate deliverability signals before your campaign reaches real recipients. The process is simple: send your draft email to a special address provided by the testing service (like Mail-Tester's unique @mail-tester.com addresses or GlockApps seed addresses), then view a detailed report scoring your authentication, content, and blocklist status.

These tools check multiple dimensions of deliverability: SPF/DKIM/DMARC authentication status, presence on major blocklists (Spamhaus, Barracuda, etc.), content analysis against spam indicators, HTML quality, link validity, and inbox placement predictions across major providers. Some services send to actual seed accounts at Gmail, Outlook, and Yahoo to report where your email actually lands-inbox, spam, or blocked entirely.

Make pre-send testing part of your standard QA workflow, especially for new templates, new sending infrastructure, or campaigns with unusual content. A score of 9-10/10 on Mail-Tester indicates good health; anything below 7 deserves investigation. These tools don't guarantee inbox placement-no tool can, but they catch obvious problems before they reach your entire list. The few minutes invested beats discovering issues from a post-send deliverability crash.