I'm not sure how to interpret this phrase:

"IMPORTANT: Beginning early 2022, we will selectively pick tenants and disable Basic Auth for all affected protocols except SMTP AUTH for a period of 12-48 hours. After this time, Basic Auth for these protocols will be re-enabled, if the tenant admin has not already re-enabled them using our self-service tools."
Does the "period of 12-48 hours" apply to smtp only, or to all the other protocols?

Anyway, this kind of indicates to me that Microsoft is doing "changes" in the way they allow us to authenticate, trying to push us away from 'legacy' authentication. There should be settings for adminstrators to re-enable these 'legacy' authentication methods. Have a read:

https://techcommunity.microsoft.com/t5/exchange-team-blog/basic-authentication-and-exchange-online-september-2021-update/ba-p/2772210 

regards

Hi everyone,

I'm just wondering if there's an accepted solution for this.  I too began experiencing the same issue as described by Juan in his original post, using Roland's original SMTP code.  I tried switching over to the code from PBNISMTP, but am still receiving the same error message about upgrading to TLS 1.2 .  I've attached the screenshot showing the error, as well as the SMTP settings, which match those in Miguel's post.  I tried multiple other configuration settings, but typically would then receive a generic '-4' error.

Next up, I'll try the Chilkat API as suggested by Chris, but was hoping for a non-paid solution.

Thanks in advance!

Brad

To be honest, I was running the bugGenie using outlook for sending emails and it stopped working somewhere in October. I think Microsoft has changed its policy for authentication and now you have to use a token instead of a password (or something like that). I simply stopped using Outlook and used gmail instead.

Apart from all that: I think your smtp setting might be incorrect. 

From https://www.gmass.co/blog/outlook-smtp/ :

Outlook SMTP Settings

When you need to add your Outlook.com account (or Microsoft account / Hotmail account / Live.com account / MSN account) to another mail app (like Gmail), you’ll need to use the following SMTP settings:

• SMTP Server Name: smtp.office365.com
• SMTP Port Number: 587
• SMTP Encryption Method: STARTTLS

Once you add these SMTP settings, you should be able to use another mail app to send emails from your Outlook account.

But how do you receive incoming emails?
To receive incoming emails, you’ll need to configure the IMAP settings or POP settings of the mail app you’ll be using.

Here are the IMAP settings for Outlook:

• IMAP Server Name: outlook.office365.com
• IMAP Port: 993
• IMAP Encryption Method: TLS

And here are the POP settings for Outlook:

• POP Server Name: outlook.office365.com
• POP Port: 995
• POP Encryption Method: TLS

However, to use POP, you’ll need to enable its access in Outlook.

Hello Roland

 Finally the solution unchecked "use TLS 1.0 and 1.1" hasn't worked, so I have tried with the new version in  https://www.topwizprogramming.com/pbnismtp.html

but I have not had any success....

Bellow , I have attached the snapshots. With the early versión it works fine, but with the new one it seems not to work. I have randomize the values of Connection Type, Auth Method an character Set values without any success....

Also, the message seems to be generic, where can I find out what the - 4 could mean?

Any idea to find a solution?

Thanks,

Juan Pedro Sanz Díez

I removed that SMTP example from my website due to the security library I used being out of date.

Try this one instead:

https://www.topwizprogramming.com/pbnismtp.html

It has a bulk mailer capability. The program connects to the server once, does multiple sends, and then disconnects. This makes it much faster than if it had to connect and disconnect for every send.

Hi Juan;

  I would suggest trying another SMTP inteface. For example, this one already supports TLS 1.2 & 1.3 as well  ...

https://www.example-code.com/powerbuilder/smtp_enable_tls_1_3.asp

HTH

Regards ... Chris

Hi.

Maybe you should contact Roland Smith. Anyway, in his source I see some checks for TLSv1, TLSv1_1, TLSv1_2 and even AnyTLS, so I guess that his library is compatible with TLS 1.2. Cannot help more than that. I'm not a c++ expert.

Andreas.