I was getting an error while trying to connect mautic with mail250 SMTP server

Your software
My Mautic version is:3.2.5
My PHP version is:7.3.26
My Database type and version is: i don.t really know

Your problem
My problem is:

I am a still a newbie with using mautic, i have successfully installed mautic on a web hosting server, set up the cron jobs and everything else.
I tried to connect the SMTP server (mail250) but i was getting this error below.

Unable to connect with TLS encryption Log data: ++ Starting Swift_SmtpTransport << 220 incoming-smtp.local ESMTP Welcome to SMTP service D40 >> EHLO mautic.mydomain.com << 250-incoming-smtp.local at your service, [139.59.60.225] 250-8BITMIME 250-ENHANCEDSTATUSCODES 250-AUTH PLAIN LOGIN 250-AUTH=PLAIN LOGIN 250 STARTTLS >> STARTTLS << 220 2.0.0 Ready to start TLS !! Unable to connect with TLS encryption (code: 0)
++ Starting Swift_SmtpTransport << 220 incoming-smtp.local ESMTP Welcome to SMTP service D40 >> EHLO mautic.mydomain.com << 250-incoming-smtp.local at your service, [139.59.60.225] 250-8BITMIME 250-ENHANCEDSTATUSCODES 250-AUTH PLAIN LOGIN 250-AUTH=PLAIN LOGIN 250 STARTTLS >> STARTTLS << 220 2.0.0 Ready to start TLS !! Unable to connect with TLS encryption (code: 0)

These errors are showing in the log:
[2021-02-06 18:16:41] mautic.WARNING: PHP Warning - stream_socket_enable_crypto(): SSL operation failed with code 1. OpenSSL Error messages: error:1416F086:SSL routines:tls_process_server_certificate:certificate verify failed - in file /home/domain/mautic.mydomain.com/mailer/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Transport/StreamBuffer.php - at line 94

Steps I have tried to fix the problem:
I have been trying to change the port, SMTP encryption mode and all but still can;t figure it out,