Sending bulk emails from Powershell script

Question

Hi there,

I need to know does Office365 allow to send bulk email from Powershell. I have tried Powershell script but no avail.
I have got below errors in Powershell after running the script;

Sending Notification to (emailaddress@keyman .com)
Exception calling "Send" with "1" argument(s): "Error in processing. The server response was: 5.7.3 STARTTLS is
required to send mail [PM4QW0902CA0020.usprd09.prod.outlook.com]"

Any help please.

Answer 1

You have to send using TLS 1.2:
https://office365itpros.com/2021/01/14/powershell-scripts-fail-exchange-online-tls12/

BUT - Sending Bulk Mail mail though Office 365 is not allowed:

https://learn.microsoft.com/en-us/office365/servicedescriptions/exchange-online-service-description/exchange-online-limits

Recipient rate limit: To discourage the delivery of unsolicited bulk messages, Exchange Online has recipient limits that prevent users and applications from sending large volumes of email. These limits are applied per-user to all outbound and internal messages.

Note

Exchange Online customers who need to send legitimate bulk commercial email (for example, customer newsletters) should use third-party providers that specialize in these services.

Answer 2

@Abdullah Tahir khan

Here is also a related thread which said using command below to force Send-MailMessage to use TLS 1.2 :

[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12  

Please Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.

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