VBA调用Outlook发邮件时正文与签名字体大小不一致如何解决？

• 你当前直接拼接正文HTML片段和签名HTML片段，两者是独立的样式体系，签名文件（Podpis.htm）本身自带内联字体配置，不会继承正文段落的样式设置
• 你之前编写的行内样式没有包裹引号，不符合标准CSS语法，Outlook内置的HTML解析器容错率较低，很可能直接忽略了你写的font-size:14pt配置
• 零散的HTML片段没有统一的根样式约束，正文和签名的字体规则各自生效，自然会出现大小不一致的情况

推荐通过构造完整HTML结构设置全局样式的方式解决，兼容性最强，不需要修改本地签名文件：

1. 给整个邮件内容套入标准的<html>、<head>、<body>标签结构
2. 在<head>中添加全局样式，统一设置所有内容的字体、字号
3. 规范所有行内样式的写法，属性值用双引号包裹
4. 如果你的签名本身有强制内联样式，可以额外加一步替换签名的字体规则，确保完全统一

Sub Report()
    Dim OutApp As Object
    Dim OutMail As Object
    Dim strbody As String
    Dim SigString As String
    Dim Signature As String
    Dim htmlHead As String
    
    Set OutApp = CreateObject("Outlook.Application")
    Set OutMail = OutApp.CreateItem(0)

    ' 正文内容，规范style写法加双引号
    strbody = "<p style=""font-family:arial;font-size:14pt"">Hi All,<br><br>" & _
    "please see report.<br></p>"

    SigString = Environ("appdata") & _
    "\Microsoft\Signatures\Podpis.htm"

    If Dir(SigString) <> "" Then
        Signature = GetBoiler(SigString)
        ' 可选：如果签名自带强制样式，加这两行替换统一字体
        Signature = Replace(Signature, "font-family:", "font-family:arial!important;")
        Signature = Replace(Signature, "font-size:", "font-size:14pt!important;")
    Else
        Signature = ""
    End If

    ' 全局样式头，统一所有内容字体配置
    htmlHead = "<!DOCTYPE html><html><head><style>" & _
               "body, p, div, span {font-family:arial;font-size:14pt;}" & _
               "</style></head><body>"
    
    On Error Resume Next
    With OutMail
        .SentOnBehalfOfName = "email@address.com"
        .To = "email@address.com"
        .CC = "email@address.com"
        .Subject = "Report"
        ' 拼接完整HTML结构
        .HTMLBody = htmlHead & strbody & "<br>" & Signature & "</body></html>"
        .Display
    End With
    On Error GoTo 0

    Set OutMail = Nothing
    Set OutApp = Nothing
End Sub

Function GetBoiler(ByVal sFile As String) As String
    Dim fso As Object
    Dim ts As Object
    Set fso = CreateObject("Scripting.FileSystemObject")
    Set ts = fso.GetFile(sFile).OpenAsTextStream(1, -2)
    GetBoiler = ts.readall
    ts.Close
End Function

内容的提问来源于stack exchange，提问作者turbodebil