Ubuntu郵件服務器怎樣配置DKIM簽名

在Ubuntu上配置DKIM（DomainKeys Identified Mail）簽名可以幫助提高郵件的安全性和可信度。以下是一個基本的步驟指南，幫助你在Ubuntu上配置DKIM簽名：

1. 安裝DKIM簽名工具

首先，你需要安裝一個DKIM簽名工具，比如opendkim。

sudo apt update
sudo apt install opendkim opendkim-tools

2. 生成DKIM密鑰對

使用opendkim-genkey命令生成DKIM密鑰對。

sudo opendkim-genkey -t -s mail -d yourdomain.com

• -t：生成測試密鑰。
• -s：指定選擇器名稱（例如mail）。
• -d：指定域名（例如yourdomain.com）。

這將在/etc/opendkim/keys/yourdomain.com/mail.private生成私鑰，在/etc/opendkim/keys/yourdomain.com/mail.txt生成公鑰。

3. 配置OpenDKIM

編輯OpenDKIM的配置文件/etc/opendkim.conf。

sudo nano /etc/opendkim.conf

添加或修改以下配置：

Domain yourdomain.com
Selector mail
PrivateKey /etc/opendkim/keys/yourdomain.com/mail.private

4. 配置DNS記錄

在DNS管理界面中添加一個TXT記錄，用于驗證DKIM簽名。

• 主機記錄：mail._domainkey
• 記錄類型：TXT
• 記錄值：v=DKIM1; k=rsa; p=YOUR_PUBLIC_KEY

例如：

v=DKIM1; k=rsa; p=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