Send-MailMessage -From [email protected] -Subject "Email Subject" -To [email protected] -SmtpServer smtp.com

$parameters = @{
    From = '[email protected]'
    To = '[email protected]'
    Subject = 'Email Subject'
    Attachments =  @('C:\files\samplefile1.txt','C:\files\samplefile2.txt')
    BCC = '[email protected]'
    Body = 'Email body'
    BodyAsHTML = $False
    CC = '[email protected]'
    Credential = Get-Credential
    DeliveryNotificationOption = 'onSuccess'
    Encoding = 'UTF8'
    Port = '25'
    Priority = 'High'
    SmtpServer = 'smtp.com'
    UseSSL = $True
}

# Notice: Splatting requires @ instead of $ in front of variable name
Send-MailMessage @parameters

# Define the txt which will be in the email body
$Txt_File = "c:\file.txt"

function Send_mail {
    #Define Email settings
    $EmailFrom = "[email protected]"
    $EmailTo = "[email protected]"
    $Txt_Body = Get-Content $Txt_File -RAW
    $Body = $Body_Custom + $Txt_Body
    $Subject = "Email Subject"
    $SMTPServer = "smtpserver.domain.com"
    $SMTPClient = New-Object Net.Mail.SmtpClient($SmtpServer, 25) 
    $SMTPClient.EnableSsl = $false
    $SMTPClient.Send($EmailFrom, $EmailTo, $Subject, $Body)

}

$Body_Custom = "This is what contain file.txt : "

Send_mail