General help

Hello everyone, I've noticed that our moodle installation stopped sending emails.

We are using a smtp server from our dedicated web hosting. It was working fine until the certificate expired back in september.

I renewed the certificate, I even removed the email account and domain and recreated them again.

If I use no TLS or SSL and use port 25 emails are been sent correctly but as soon as I use TLS and port 587 I get the folliwing error:

2021-10-12 11:30:17	Connection: opening to academytotemguard.com:587, timeout=300, options=array()
2021-10-12 11:30:17	Connection: opened
2021-10-12 11:30:17	SERVER -> CLIENT: 220 *****.******.eu ESMTP Postfix (Ubuntu)
2021-10-12 11:30:17	CLIENT -> SERVER: EHLO plataforma.totemguard.com
2021-10-12 11:30:17	SERVER -> CLIENT: 250-*****.ip-******.eu
                   	                  250-PIPELINING
                   	                  250-SIZE 10240000
                   	                  250-ETRN
                   	                  250-STARTTLS
                   	                  250-ENHANCEDSTATUSCODES
                   	                  250-8BITMIME
                   	                  250-DSN
                   	                  250-SMTPUTF8
                   	                  250 CHUNKING
2021-10-12 11:30:17	CLIENT -> SERVER: STARTTLS
2021-10-12 11:30:17	SERVER -> CLIENT: 220 2.0.0 Ready to start TLS
2021-10-12 11:30:17	Connection failed. Error #2: stream_socket_enable_crypto(): SSL operation failed with code 1. OpenSSL Error messages:
                   	                  error:14090086:SSL routines:ssl3_get_server_certificate:certificate verify failed [/var/www/vhosts/******/plataforma/lib/phpmailer/src/SMTP.php line 403]
2021-10-12 11:30:17	SMTP Error: Could not connect to SMTP host.
2021-10-12 11:30:17	CLIENT -> SERVER: QUIT
2021-10-12 11:30:17	SERVER -> CLIENT: MIAx&/9΅L3Ax0-9(Vto0O@@gR[Tb݇Vv(VٷhːN)̗,HxzB;IOPLz;~&orRi3k
                   	                  |8iVl*;HHDhZWHdt2yKhH!nGP@YQ9wYa $$ӽ.Ȅ:LLFM|3#
2021-10-12 11:30:17	SMTP ERROR: QUIT command failed: MIAx&/9΅L3Ax0-9(Vto0O@@gR[Tb݇Vv(VٷhːN)̗,HxzB;IOPLz;~&orRi3k
                   	                  |8iVl*;HHDhZWHdt2yKhH!nGP@YQ9wYa $$ӽ.Ȅ:LLFM|3#
2021-10-12 11:30:17	Connection: closed
2021-10-12 11:30:17	SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting

At this point I don't know what is failing because I've tested other email apps such us the webmail from our webhosting and the email app from Windows 10 with the same settings as moodle and it works no problem in both places.

Please let me know if you need any further assistance

I'd appriciate any help you can provide

Thanks in advance