Excel VBA发送邮件时字体大小与代码指定不符问题排查

你的代码里用<font>标签指定字体大小时写法错误。HTML的<font>标签的size属性不支持带pt的单位，它只能接受1到7的数字（1最小，7最大）。你写size="11pt"这种格式，Outlook会识别为无效值，直接 fallback 到默认的超大字号（也就是你看到的36pt）。

要正确设置字号，得改用CSS的font-size属性，把样式写在style属性里，而非<font>的size属性。修改后的代码如下：

Sub SendEmail(Body as String, EmailTo as String, EmailCC as String, EmailSubject as String, Message as String, Title as String)
Dim EmailApp As Outlook.Application
Set EmailApp = New Outlook.Application

Dim Email As Outlook.MailItem

' 用style属性指定完整字体样式，包括正确的字号单位
Body = "<span style=""font-family:Calibri; font-size:11pt; color:#000000"">" & Message & "</span>"
Signature = "<span style=""font-family:Arial; font-size:11pt; color:#808080"">Kind regards<br><br></span>" & _
            "<span style=""font-family:Arial; font-size:10pt; color:#808080"">" & Title & "</span>"

Set Email = EmailApp.CreateItem(olMailItem)
Email.To = EmailTo
Email.CC = EmailCC
Email.Subject = EmailSubject
Email.HTMLBody = Body & "<br><br>" & Signature ' HTML中用<br>实现换行，vbNewLine无效
Email.Send
End Sub

额外补充两点：

• 原代码里的vbNewLine在HTML邮件中不会生效，必须换成<br>标签来实现换行
• <font>标签属于已废弃的HTML标签，用<span>配合style属性更符合现代规范

内容的提问来源于stack exchange，提问作者Jens