如何用PowerShell发送邮件？执行代码遇连接关闭错误求助

API 探路者

2026-8-18

使用PowerShell通过Yahoo SMTP发送邮件时出现net_io_connectionclosed错误的解决方法

问题重现

尝试使用PowerShell发送邮件，代码如下：

$Username = "test@yahoo.com"
$Password = "testpassword"
 
$SecurePassword = $Password | ConvertTo-SecureString -AsPlainText -Force
$Credentials = New-Object System.Management.Automation.PSCredential -ArgumentList $Username, $SecurePassword
 
$RcptTo = "somebody@mailserver.com"
$Subject = "Yahoo Test"
$Body = "This is a test message"
Send-MailMessage -From $Username -To $RcptTo -Subject $Subject -Body $Body -SmtpServer smtp.mail.yahoo.com -Port 587 -UseSsl -Credential $Credentials

执行后报错：

Send-MailMessage : Unable to read data from the transport connection: net_io_connectionclosed.

解决步骤

1. 改用Yahoo应用专用密码

Yahoo已禁用普通账户密码用于SMTP验证，必须生成应用专用密码：

登录Yahoo账户，进入「账户安全」页面
开启「两步验证」（若未开启）
在「应用专用密码」板块，生成一个针对邮件客户端的专用密码
将代码中的$Password替换为该专用密码

2. 验证网络与端口可用性

确认本地防火墙、杀毒软件或网络代理未拦截587端口
保留-UseSsl参数，Yahoo SMTP强制要求SSL加密连接

3. 替换为`System.Net.Mail`实现（推荐）

Send-MailMessage是已弃用的cmdlet，改用.NET原生类兼容性更佳：

$Username = "test@yahoo.com"
$AppPassword = "你的应用专用密码"

$smtpClient = New-Object System.Net.Mail.SmtpClient("smtp.mail.yahoo.com", 587)
$smtpClient.EnableSsl = $true
$smtpClient.Credentials = New-Object System.Net.NetworkCredential($Username, $AppPassword)

$mailMessage = New-Object System.Net.Mail.MailMessage
$mailMessage.From = $Username
$mailMessage.To.Add("somebody@mailserver.com")
$mailMessage.Subject = "Yahoo Test"
$mailMessage.Body = "This is a test message"

try {
    $smtpClient.Send($mailMessage)
    Write-Host "邮件发送成功"
} catch {
    Write-Host "发送失败: $_"
}