Sending mail from powershell - powershell

Question

I have a task to send some 500 e-mails and I'm exploring the best (easiest) way to do that. I came across some Powershell examples but I can't make it work. I see there are 2 approaches: create a script and then call it from powershell command line, or do it directly from command line. The second approach would be better for me because it would be easier to generate those command lines for 500 e-mails. I found some examples and come to this:
$smtp = New-Object Net.Mail.SmtpClient("smtp.gmail.com", "465")
$Smtp.EnableSsl = $true
$Smtp.Credentials = New-Object System.Net.NetworkCredential("myusername","mypass")
$Smtp.Attachments.Add("C:\bla.txt")
$smtp.Send("myusername#gmail.com","someusername#gmail.com","Test Email","This is a test")
For the first attempt I'm trying to send mail from gmail...
I'm not good in Powershell (better to say, don't know it at all but have some general knowledge about command line from command prompt/MS-DOS which is more familiar to me).
Also will, mail server allow sending 500 e-mails like this or it will recognize it as some attack, spam, whatever...?
I would appreciate any help.
Thanks!
EDIT:
I have also tried this:
$From = "YourEmail#gmail.com"
$To = "AnotherEmail#YourDomain.com"
$Cc = "YourBoss#YourDomain.com"
$Subject = "Email Subject"
$Body = "Insert body text here"
$SMTPServer = "smtp.gmail.com"
$SMTPPort = "465"
Send-MailMessage -From $From -to $To -Cc $Cc -Subject $Subject -Body $Body -SmtpServer $SMTPServer -port $SMTPPort -UseSsl -Credential (Get-Credential)
For $From, $To, $Cc I have put my real e-mail address
Error I got is this:
Send-MailMessage : Unable to read data from the transport connection: net_io_connectionclosed.
At line:9 char:1
+ Send-MailMessage -From $From -to $To -Cc $Cc -Subject $Subject -Body ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidOperation: (System.Net.Mail.SmtpClient:SmtpClient) [Send-MailMessage], SmtpException
+ FullyQualifiedErrorId : SmtpException,Microsoft.PowerShell.Commands.SendMailMessage

Answer 1

According to Gmail's Support Page Gmail's limit on the the number of emails sent via the SMTP relay service (for G Suite accounts) is 10,000 emails every 24 hours. If you exceed the limit, you will receive an HTTP 550 error and will be banned from sending emails for the next 24 hours. If you do not have a G Suite account, the limit is 500 per 24 hours. Exceeding this also will result in a 550 error and a 24 hour ban from use of Gmail. Also, Gmail only allows non-G Suite users to send emails to 100 recipients per email over the SMTP relay, so if you did send the email to your email list it would have to be split into multiple emails.
As such, I would not recommend sending your 500+ emails via Google's SMTP service unless you have G Suite account, as it may have your account disabled for 24 hours and any messages sent past the 500 email limit will be blocked.

Answer 2

(I think think you can use your company's email server or some server let you send more than 500 email.)
Setting your gmail smtp server. You will get a application password.
encryption your password
Read-Host "Enter gmail application password" -AsSecureString | ConvertFrom-SecureString | Out-File "$HOME\Desktop\SendEmailUse.txt"
Than you can send email (auto login)
$emailFrom = "sendFrom#gmail.com"
$sendto = "sendTo-1#gmail.com"
$sendto2 = "sendTo-2#yahoo.com.tw" # -cc -bcc
$runDateTime = Get-Date
$Subject = "Script Run Completed - $runDateTime" # title
$attachmentLocation = "$HOME\Desktop\ScheduledJobLog.txt" # -Attachments
$emailBody = #"
This is PowerShell sent mail test.
at $runDateTime
"#
$pwdfile = "$HOME\Desktop\SendEmailUse.txt"
$emailSmtpServer = "smtp.gmail.com"
$port = "587"
$pwd = (Get-Content $pwdfile | ConvertTo-SecureString)
$creds = New-Object System.Management.Automation.PSCredential($emailFrom, $pwd)
Send-MailMessage -From $emailFrom -To $sendto -Cc $sendto2 -SmtpServer $emailSmtpServer -Port $port -Credential $creds -UseSsl -Body $emailBody -Encoding 'utf8' -Subject $Subject -Attachments $attachmentLocation
Write-Output "Email Sented."