Send-MailMessage : The SMTP server requires a secure connection... The server response was: 5.5.1 Authentication Required.

Question

Alright so as the title says, I get this error when trying to send email via PowerShell:

Send-MailMessage : The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.5.1 Authentication Required.

I have looked at numerous questions related to the same issue. But I can't seem to make my script work:

    #Email alerts when a user gets locked out
##############################################################################
$pass = Get-Content .\securepass.txt | ConvertTo-SecureString -AsPlainText -Force
$name = "[email protected]"
$cred = New-Object System.Management.Automation.PSCredential($name,$pass)
##############################################################################
$From = "[email protected]"
$To = "[email protected]"
$Subject = "User Locked Out"
$Body = "A user has been locked out of his/her account."
$SMTPServer = "smtp.gmail.com"
$SMTPPort = "587"

Send-MailMessage -From $From -to $To -Subject $Subject `
-Body $Body -SmtpServer $SMTPServer -port $SMTPPort `
-Credential $cred -UseSsl
##############################################################################

I have logged into the Gmail account from the machine that will be running the script. I have also enabled Access for less secure apps from the Google account manager. I do get this to work just fine if I prompt for the credentials using the -Credential (Get-Credential) instead of calling for the $cred variable.

Is there something I am missing?

Thanks, Dan

Answer 1

If the file contains the encrypted password it's better to read it like this (without the parameters -AsPlainText and -Force):

$pass = Get-Content .\securepass.txt | ConvertTo-SecureString

Demonstration:

PS C:\> $sec = 'foobar' | ConvertTo-SecureString -AsPlainText -Force
PS C:\> $sec
System.Security.SecureString
PS C:\> $txt = $sec | ConvertFrom-SecureString
PS C:\> $txt
01000000d08c9ddf0115d1118c7a00c04fc297eb01000000615ce070639b9647a5e05d42b41d373
0000000000200000000001066000000010000200000001614c19281e7c0b076cceb38e284b0f18b
c0d813ea40ed055dde96fd9ccb6977000000000e8000000002000020000000a10c7019eb224c3c6
387ba03bcd94993a50e0c468248284bbce4d235b11f1b94100000002421a5d7102de13c46ccc1db
c4921287400000000412332ecb500828f4403f3e225089c629369744bad62609b528ed0a7318abf
512c9b6a8884c43b3adc8a13d5d21a9ed27e56702bcc7db094da9d9d4c02dfa74
PS C:\> $sec2 = $txt | ConvertTo-SecureString
PS C:\> $sec2
System.Security.SecureString
PS C:\> $cred = New-Object Management.Automation.PSCredential 'foo', $sec2
PS C:\> $cred.GetNetworkCredential().Password
foobar

Beware though that encryption of secure strings is tied to the user and host encrypting them, meaning you can't decrypt a secure string on another host or as another user.