ubuntu郵件服務器DKIM簽名設置

在Ubuntu上設置郵件服務器的DKIM（DomainKeys Identified Mail）簽名可以幫助提高郵件的可信度和防止偽造。以下是一個基本的步驟指南，使用opendkim和opendkim-tools來設置DKIM簽名。

1. 安裝必要的軟件包

首先，更新你的包列表并安裝opendkim和opendkim-tools：

sudo apt update
sudo apt install opendkim opendkim-tools

2. 配置OpenDKIM

生成密鑰對

你需要為你的域名生成一個DKIM密鑰對?？梢允褂靡韵旅钌桑?/p>

sudo opendkim-genkey -t -s mail -d 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。

配置OpenDKIM

編輯OpenDKIM的主配置文件/etc/opendkim.conf，進行如下配置：

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

配置DNS記錄

你需要在你的DNS提供商處添加一個TXT記錄，以便郵件接收方可以驗證DKIM簽名。TXT記錄的內容應該是：

selector._domainkey IN TXT "v=DKIM1; k=rsa; p=YOUR_PUBLIC_KEY"

將selector替換為你在opendkim.conf中配置的Selector值，將YOUR_PUBLIC_KEY替換為/etc/opendkim/keys/yourdomain.com/mail.txt文件中的內容。

例如：

mail._domainkey IN TXT "v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC8kGa1pSjbSYZVebtTRBLxBz5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lFJy9z5H4I6tj6hV7y2wVbEeJm5lF