Email Marketing Infrastructure in India: The Deliverability Guide
"Why are my marketing emails going to spam?" is one of the most common support questions we get from Indian businesses — and it's almost never about the email content. It's about infrastructure: authentication records, sending reputation, and mixing transactional mail with bulk marketing mail on the same domain. Here's how to actually fix it.
The three authentication records you need
- SPF — tells receiving servers which mail servers are allowed to send on behalf of your domain
- DKIM — cryptographically signs each email so receivers can verify it wasn't altered or spoofed
- DMARC — tells Gmail/Outlook what to do if SPF or DKIM fails, and gives you visibility into spoofing attempts
Setting Up DNS Records
Add an SPF record
v=spf1 include:_spf.hoststack.pro ~all if using Hoststack mail, or include your marketing platform's SPF include (e.g. Zoho, Sendinblue, Mailchimp) alongside it. Only one SPF record is allowed per domain — merge all senders into it.Enable DKIM in your email/marketing platform
Publish a DMARC policy
v=DMARC1; p=none; rua=mailto:[email protected] to monitor without rejecting mail, then move to p=quarantine after a few weeks once you've confirmed all legitimate senders pass.Separate transactional and marketing mail
[email protected], and newsletters from [email protected] or a subdomain like mail.yourdomain.com. If a bulk campaign gets marked as spam, it won't drag down deliverability for critical transactional email.Transactional vs. Bulk Marketing Sending
Transactional (SMTP/API)
Order confirmations, OTPs, password resets. Low volume, must arrive instantly. A standard Hoststack hosting mailbox or an SMTP relay works fine here.
Bulk marketing
Newsletters, promotions to thousands of recipients at once. Needs a dedicated marketing platform with list hygiene, unsubscribe handling, and reputation management — never send bulk campaigns through a regular hosting mailbox.
Why regular hosting mailboxes fail at bulk sending
A shared hosting mail server is built for normal business email volume, not a 20,000-recipient blast. Sending bulk campaigns through it risks getting your entire IP range rate-limited or blacklisted, which can take down transactional email too. Use a dedicated email marketing platform (Zoho Campaigns, Brevo, Mailchimp) that manages IP warmup and reputation for bulk sends, while keeping transactional mail on your hosting mailbox or a lightweight SMTP API.
List Hygiene Matters More Than Content
Gmail and Outlook track engagement per sending domain — opens, clicks, and complaints. Sending to a stale list full of dead addresses tanks your sender score regardless of how well-written the email is. Remove hard bounces immediately, suppress addresses that haven't opened anything in 6+ months, and always include a working one-click unsubscribe link — required under most platforms' policies and it prevents spam complaints, which hurt reputation far more than unsubscribes do.
Quick Summary
- 1 Set up SPF, DKIM, and DMARC — all three, correctly merged
- 2 Separate transactional and marketing mail onto different addresses
- 3 Never send bulk campaigns through a regular hosting mailbox
- 4 Keep your list clean — remove bounces and inactive addresses
- 5 Monitor DMARC reports to catch spoofing and delivery issues early
Need reliable business email?
Hoststack email hosting includes SPF/DKIM setup support, spam filtering, and generous mailbox storage — starting at ₹39/month.
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