STARTTLS is required when trying to send an email within SQL Server

Jason Yeung 66

Hi,
I'm trying to setup a couple of alerts on SQL Server which sends me a message when the alert executes. I've setup an account in Database Mail, which sends an email via "smtp.office365.com", using port 587. Below is the settings I used (I removed the domain of the accounts for security purposes):

When I to send a test message, I get the following errors, depending on whether I have the "This server requires a secure connection" checkbox checked.

If this checkbox is not checked, I get:
Exception message: cannot send mails to mail. The server response was 5.7.3 STARTTLS is required to send mail

If this checkbox is checked, I get:
The server response was 5.7.57 Client not authenticated to send mail.

I also tried port 25, basic and anonymous authentication and a variety of users when using basic authentication, but the same errors appear. I was wondering how do I set the account up so I could send a message from SQL Server?

Sincerely,

Jason

Mor Levi 21 Reputation points

2022-04-28T09:45:22.783+00:00

Have the same error! in my 365mail marked autenticated SMTP...

and in my logged - "General Error System.Net.Mail.SmtpException: Error in processing. The server response was: 5.7.3 STARTTLS is required to send mail [******.eurprd02.prod.outlook.com]
at System.Net.Mail.MailCommand.CheckResponse(SmtpStatusCode statusCode, String response)
at System.Net.Mail.MailCommand.Send(SmtpConnection conn, Byte[] command, MailAddress from, Boolean allowUnicode)
at System.Net.Mail.SmtpTransport.SendMail(MailAddress sender, MailAddressCollection recipients, String deliveryNotify, Boolean allowUnicode, SmtpFailedRecipientException& exception)
at System.Net.Mail.SmtpClient.Send(MailMessage message)
at NotificationLib.SmtpMailSender.Send(Dictionary`2 config)"

Do you have eny solution ? getting crazy because of that
Thank you!

6 answers

AmeliaGu-MSFT 13,986 Reputation points Microsoft Vendor

2021-03-19T06:15:11.253+00:00

Hi JasonYeung-2529,
What the version of SQL Server and OS are you using?
Please refer to this doc to check if TLS 1.2 is supported for your OS and SQL Server, and make sure the TLS 1.2 is enabled.
And here is a tool which may help you to manage protocols.

Best Regards,
Amelia

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Tooth Fairy's Tale 1 Reputation point

2021-09-15T12:20:31.08+00:00

I am having a problem with sending my email from a certain program. Even though it is set up using STARTTLS, I am getting an error message saying 451 5.7.3 STARTTLS is required to send mail [BYAPR11CA0103.namprd11.prod.outlook.com] I am so frustrated with this! Can someone PLEASE help me!! Thank you!!
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Francesco Mantovani 1 Reputation point

2021-06-10T08:48:05.093+00:00

nartac didn't worked.
It's particularly bad because I'm using Windows Authentication
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Tom Phillips 17,741 Reputation points

2021-09-15T12:46:43.597+00:00

The box "This Server requires a secure connection (SSL)" must be checked.

Lucas Igbins 0 Reputation points

2024-01-12T23:04:17.0366667+00:00

@Francesco Mantovani how did you fix your issue? I am getting similar error message. Any help. The mail could not be sent to the recipients because of the mail server failure. (Sending Mail using Account 1 (2024-01-12T22:30:04). Exception Message: Cannot send mails to mail server. (Error in processing. The server response was: 5.7.3 STARTTLS is required to send mail [namprd11.prod.outlook.com :]).
) Smtp client authen is enable for the mailbox. Server/smart hostsmtp.office365.comPortPort 587 (recommended) or port 25TLS/StartTLSEnabledUsername/email address and passwordSign in credentials of Microsoft 365 or Office 365 mailbox the printer uses
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Tooth Fairy's Tale 1 Reputation point

2021-09-15T12:53:45.997+00:00

Thank you TomPhillips-1744 for replying!! when I click the box, then it says, "The token supplied to the function is invalid" ?? (this is the program I am trying to send emails from called IBP) Is there another place I need to check that box?
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Tom Phillips 17,741 Reputation points

2021-09-15T15:33:49.733+00:00

This error is related to this problem.
https://support.microsoft.com/en-us/topic/ms12-006-vulnerability-in-ssl-tls-could-allow-information-disclosure-january-10-2012-41786996-65e1-ad9e-7536-fdc4017a81a1

Use regedit to change SCHANNEL to 2.
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Tooth Fairy's Tale 1 Reputation point

2021-09-15T13:00:09.357+00:00

Should incoming mail be set at: SSL/TLS and outgoing set as: STARTTLS? However, in the outlook account settings, I'm not seeing a box to check for SSL?
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Tooth Fairy's Tale 1 Reputation point

2021-09-15T13:03:54.45+00:00

If the above is correct, it is set at that... so I wonder what I am missing or doing wrong?
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Francesco Mantovani 1 Reputation point

2021-09-15T20:03:10.44+00:00

Hi, I wrote an article that might help you out: https://www.jeeja.biz/2021/07/01/sql-server-why-your-database-mail-is-not-working-and-probably-never-will/

Tooth Fairy's Tale 1 Reputation point

2021-09-15T23:20:15.12+00:00

Oh wow, so you created this yourself? And it's free? I wish I understood computers more and how to install it, I am so new at all this... but I am going to keep this and see if I can attempt it one day. I'm just afraid I will mess something up in my computer that i won't be able to fix... sigh! But thanks for this, it is greatly appreciated! :))

Francesco Mantovani 1 Reputation point

2021-09-16T19:20:48.243+00:00

Don't be afraid. Edit the first few lines, paste it in a SSMS tab and press F5.
The query will install the account for you.
If it doesn't work or if it brakes stuff.... this is how we all learnt.
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STARTTLS is required when trying to send an email within SQL Server

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