Email Deliverability Guide

How to improve email deliverability and stay out of spam

A practical guide to SPF, DKIM, DMARC, list hygiene and sending habits that help your emails reach the inbox.

Email Deliverability Guide

SPF and DKIM
DMARC policy
Clean lists

Email Deliverability Guide: the short answer

To improve email deliverability, authenticate your sending domain with SPF, DKIM and DMARC, send only to people who opted in, remove bounced and inactive addresses, keep spam complaints low and send consistent volumes. Mailbox providers reward senders who are authenticated, wanted and predictable.

This page is part of our Email Marketing service. See also bulk email service and transactional email. Ready to start? Book a demo or talk to our team.

How to get started

Publish SPF and DKIM records for your sending domain and add a DMARC policy.
Collect consent and add a clear, one-click unsubscribe to marketing email.
Clean your list: remove hard bounces and long-inactive contacts.
Ramp volumes up gradually and monitor complaints and bounces.

Last updated: 24 October 2026

At a glance

Topic	Email deliverability
Key controls	SPF, DKIM, DMARC, consent, list hygiene
Complaint rate goal	Keep spam complaints well below 0.3% (Google guidance)
Applies to	Marketing and transactional email
Last reviewed	24 October 2026
Contact	sales@mantraxtel.com, +91 82188 68212 (Mon-Fri, 9:30 AM-6:30 PM IST)

What decides whether an email reaches the inbox

Mailbox providers such as Gmail and Yahoo decide where each email lands using signals about the sender: is the domain authenticated, do recipients engage or complain, and does the sending pattern look normal. Since 2024, Gmail and Yahoo have also required authentication and easy unsubscribe from senders who mail in bulk.

None of this needs to be complicated. A short checklist, followed consistently, solves most deliverability problems before they start.

SPF lists the servers allowed to send for your domain
DKIM adds a signature that proves the message was not altered
DMARC tells providers what to do if SPF or DKIM fail, and sends you reports
A one-click unsubscribe link in every marketing email
A spam complaint rate kept as low as possible, under 0.3%

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Habits that protect your sender reputation

Send to engaged people

Prioritise contacts who open and click, and rest those who never do.

Keep lists clean

Remove hard bounces immediately and re-confirm old contacts.

Warm up gradually

Increase volume step by step when you start on a new domain.

Separate your streams

Keep transactional and promotional email on different sending paths.

Where Mantraxtel helps

Sender setup is part of Mantraxtel onboarding, and delivery, open and click reports help you spot problems early. If open rates fall or bounces rise, treat it as a signal to review your list and content.

For the full picture of sending, see our bulk email service and transactional email service.

Email Deliverability Guide: questions, answered.

Clear answers to the questions we hear most. If yours is not here, ask us directly.

What is email deliverability?

Email deliverability is the ability of your emails to reach the recipient's inbox rather than the spam folder or being blocked. It depends on your domain authentication, reputation, list quality and content.

What are SPF, DKIM and DMARC?

SPF lists the servers allowed to send email for your domain. DKIM adds a cryptographic signature to prove a message is genuine. DMARC tells mailbox providers how to handle messages that fail those checks and gives you reports.

Why do my emails go to spam?

Common causes are missing authentication, a purchased or old list, high complaint or bounce rates, sudden jumps in volume and spammy content. Fixing authentication and list quality resolves most cases.

What is a good spam complaint rate?

Google advises senders to keep the spam rate below 0.3% and ideally far lower. Lower is always better, so focus on sending to people who asked to hear from you.

Does Mantraxtel help with sender setup?

Yes. Sender setup is part of onboarding, and our team can guide you on authentication and good sending practice for your volume.

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