SQL Server 2016 Database Mail cannot send email smtp.office365.com

Question

SQL Server 2016 Database Mail and I get this error: Message The mail could not be sent to the recipients because of the mail server failure. (Sending Mail using Account 3 (2020-12-02T22:03:59). Exception Message: Cannot send mails to mail server. (Failure sending mail.). ) The configuration I use
Server: smtp.office365.com Port Number: 587 Authentication: Basic (An email address and password)

The server has disabled all SSL3 TLS 1.0 and 1.1, enabled TLS 1.2 Also .NET 4.7.1

Still not working...

Answer 1

Hi @drcz ,
In addition, have you ticked “This server requires a secure connection(SSL)” in account tab?
Please refer to this similar thread:

Below is the content for a simple executable registry file that I put together that will make the 2 new settings and the settings already shown on the thread above (i.e. this makes all of the necessary Registry settings*):
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft.NETFramework\v4.0.30319]
"SchUseStrongCrypto"=dword:00000001

[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft.NETFramework\v4.0.30319]
"SchUseStrongCrypto"=dword:00000001

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2]

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Client]
"DisabledByDefault"=dword:00000000
"Enabled"=dword:00000001

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\TLS 1.2\Server]
"DisabledByDefault"=dword:00000000
"Enabled"=dword:00000001
Note 1: SQL needs to be restarted for these settings to take affect but it is better to restart Windows since the new settings will affect .NET 4.x generally.

Note 2: In SQL, the SSL-checkbox must be ticked in the mail profile to use TLS1.2.

Best Regards,
Amelia

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Answer 2

Have you read How to set up a multifunction device or application to send email using Microsoft 365 or Office 365 for all required steps?

Answer 3

I have seen the article just that I could not find the settings in a personal account. Is that working in the same way?

Answer 4

Hi @drcz ,
Could you please use Telnet to test SMTP communication?
Please refer to Use Telnet to test SMTP communication and Testing SMTP with authentication from the command line which might help.
In addition, quoting from this support article:

Assume that you install Microsoft SQL Server 2016 on a computer that has the .NET Framework 4.6.1 installed. If the computer does not have the .NET Framework 3.5 installed, the Database Mail feature does not work correctly. For example, if you configure and send a test email message, the message is queued but is never sent.

Please try to install SP1 and CU2 for SQL Server 2016.
And to work around this issue, you can implement any one of the following:

1. Create the DatabaseMail.exe.config and drop it next to the DatabaseMail.exe under the Binn folder. You can use notepad.exe or any other editor to edit it and save it by using UTF-8 encoding (in notepad.exe, select Save As... and in the Encoding combo box, select UTF-8):

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<startup useLegacyV2RuntimeActivationPolicy="true">
<supportedRuntime version="v4.0"/>
<supportedRuntime version="v2.0.50727"/>
</startup>
</configuration>

2. Run a repair setup action of SQL Server 2016.
3. Manually install .Net Framework 3.5 on the machine.
   Best Regards,
   Amelia

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Answer 5

Hi @AmeliaGu-MSFT
is help me to do few more steps what did you send.

My first step was to Use telnet to check.

Send-MailMessage –From from@domain.com –To to@domain.com –Subject “Test Email” –Body “Test SMTP Relay Service” -SmtpServer smtp.office365.com -Credential $msolcred -UseSsl -Port 587  

initially I had this error solved with [System.Net.ServicePointManager]::SecurityProtocol = [System.Net.SecurityProtocolType]::Tls12

Send-MailMessage : The client and server cannot communicate, because they do not possess a common algorithm
At line:1 char:1

• Send-MailMessage –From from@keyman .com –To to@keyman .com ...
• ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
• CategoryInfo : InvalidOperation: (System.Net.Mail.SmtpClient:SmtpClient) [Send-MailMessage], SmtpExcept
  ion
• FullyQualifiedErrorId : SmtpException,Microsoft.PowerShell.Commands.SendMailMessage

meanwhile I have installed 3.5, uninstalled, then installed .net 4.8. and looks like SQL Serve it was updated to SP1 and CU. The same error when I try to send form Database Mail:

Message
The mail could not be sent to the recipients because of the mail server failure. (Sending Mail using Account 3 (2020-12-04T12:29:26). Exception Message: Cannot send mails to mail server. (Failure sending mail.).
)