> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sendify.dingstore.cn/llms.txt
> Use this file to discover all available pages before exploring further.

# Improve Gmail deliverability

> Use authentication, domain warm-up, and monitoring to reduce Gmail spam placement

Gmail uses strict, adaptive spam filtering. New sending domains and IP addresses may be filtered or rejected if they have not built a positive reputation. This guide outlines a practical warm-up process. See Google's [Email sender guidelines](https://support.google.com/a/answer/81126) for current requirements.

## 1. Complete the technical setup

### Configure SPF, DKIM, and DMARC

* **SPF:** Lists the servers allowed to send for your domain.
* **DKIM:** Adds a signature that proves the message was authorized and not modified in transit.
* **DMARC:** Tells Gmail how to handle messages that fail authentication and enables domain-abuse reporting.

> [!NOTE]
>
> During initial warm-up, consider a DMARC policy of `p=none` so you can monitor results before enforcing rejection.

See [Add and verify a sending domain](https://docs.sendify.dingstore.cn/en/sending-domain.md) for configuration instructions.

### Configure Google Postmaster Tools

Verify your sending domain in [Google Postmaster Tools](https://postmaster.google.com/).

![Google Postmaster Tools](https://mintcdn.com/sendify-3a1f7fa4/kc5dBtMpq5V05V0e/gmail-postmaster.png?fit=max\&auto=format\&n=kc5dBtMpq5V05V0e\&q=85\&s=8ff5c9dfbbca9f7a3b2b3312e77cac1b)

Use it to monitor domain and IP reputation, authentication rates, delivery errors, and spam complaints.

## 2. Warm up gradually

Start with a small, high-quality, engaged audience and increase volume steadily.

* Prioritize users active within the last 30 days who explicitly agreed to receive email.
* Never warm up with purchased, stale, or unconfirmed lists.
* Positive opens, clicks, and “not spam” actions help build reputation.

| Stage | Suggested approach |
| - | - |
| Days 1–3 | Send to 200–1,000 of your most active Gmail users and monitor closely |
| Days 4–7 | If engagement is healthy and complaints are near zero, increase gradually, for example 200 → 400 → 800 |
| Days 8–14 | Continue stable growth, for example 1,500 → 3,000 → 6,000 per day |

> [!WARNING]
>
> If complaints rise or open rates fall sharply, stop increasing volume and investigate content and list quality.

Avoid sudden spikes such as moving from 100 messages per day to 100,000.

## 3. Monitor and optimize

* Keep spam complaints below **0.3%**.
* Keep hard bounces below **0.5%** and clean invalid addresses.
* Monitor opens and clicks as engagement signals.
* Include a clear unsubscribe link in every message.
* Send relevant content and avoid excessive capitalization, punctuation, or image-heavy layouts.

See [Manage unsubscribes](https://docs.sendify.dingstore.cn/en/unsubscribe.md) for unsubscribe setup.

## Pre-send checklist

* SPF, DKIM, and DMARC are configured correctly.
* The domain is verified in Google Postmaster Tools.
* The first audience contains recent, engaged Gmail users.
* Volume increases gradually and consistently.
* Complaint and bounce metrics are monitored.
* Every message provides value and an easy way to unsubscribe.


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