Cold email deliverability, from DNS to sending limits.
Learn how 17Signal checks email addresses, sets up your sending domain, warms mailboxes, and spaces out emails to protect your reputation.
Generate verified DNS records for any secondary domain
The Four Pillars of High Inbox Placement
Every sending node in 17Signal enforces all 4 pillars automatically.
1. Cryptographic Authentication
SPF, DKIM, and DMARC prevent domain spoofing and prove to Google and Microsoft that your messages originate from an authorized mail relay.
2. Dynamic Sender Rotation
Never blast 500 emails from a single mailbox. We rotate volume across multiple secondary domains and mailboxes, capping each at ~30 sends per day.
3. Humanized Jitter & Pacing
Batched volume bursts trigger instant spam filters. 17Signal introduces randomized 45–180s delays during the recipient's local timezone.
4. Emails Based on Research
Claude Sonnet 5 writes short emails using facts found during research. Check the messages and watch replies before sending more.