Email Config for office365 on port 587

I need to adjust  Email config to use office365 on port 587.  However after making the change , email fails, throwing the following error:

projeqtor.php' at line (2932)
cause = mail(): SMTP server response: 451 5.7.3 STARTTLS is required to send mail [BLAPR03CA0092.namprd03.prod.NotAllowedScript68cd84efe1593outlook.com 2025-09-16T17:42:53.030Z 08DDF4198AE707FA]
2025-09-16 13:42:53.108 ***** ERROR ***** [V10.3.4] Error sending mail
2025-09-16 13:42:53.109 ***** ERROR ***** [V10.3.4]    SMTP Server : smtp.office365.com
2025-09-16 13:42:53.110 ***** ERROR ***** [V10.3.4]    SMTP Port : 587
2025-09-16 13:42:53.111 ***** ERROR ***** [V10.3.4]    Sendmail path : 
2025-09-16 13:42:53.112 ***** ERROR ***** [V10.3.4]    Mail stored in Database : #19322

My first thought is the issue is related to SSL . 

When I try to use Library PHPMailer (recommended) with the SMTP settings above I am also seeing 
Extension missing: openssl.

Any help or insight would be greatly appreciated.    Thank you in advance.