Cold Email Deliverability in India: Stop Landing in Spam (SPF, DKIM & Warm-up Explained Simply)

Why Your Emails Go to Spam

Gmail and Outlook judge three things: is the sender authenticated (SPF/DKIM), does the domain have history (warm-up), and do humans engage (opens/replies). Fail any one and the best-written email in India dies in a spam folder.

The 30-Minute Setup

1. Buy a sister domain (yourbrand-mail.in) — never risk your main domain.
2. Add SPF: one TXT record listing who may send for you.
3. Add DKIM: your provider (Resend, Google) gives you the record — it cryptographically signs each mail.
4. Add DMARC: v=DMARC1; p=quarantine tells inboxes to trust the first two.
5. Verify in your sending tool before the first send.

Warm-up and Volume Rules

New domains must earn trust: 10–15 emails/day in week one, doubling weekly, replies matter more than volume. Hard ceiling around 50–100 cold emails per inbox per day even when warm. Spintax variation and personalised first lines keep pattern-detectors calm.

The Compliance Bits That Also Help Inboxing

One-click unsubscribe headers (Gmail now requires them for bulk senders), a real postal identity, and instant suppression of opt-outs. LeadRadar adds the List-Unsubscribe header and a suppression list automatically on every send — compliance that doubles as deliverability.

Checklist before your next campaign: sister domain ✔ SPF ✔ DKIM ✔ DMARC ✔ 2-week warm-up ✔ under 100/day ✔ unsubscribe link ✔. Do this once and your open rates will stop lying to you.