aaPanel_Kern
Hello Mr
unfortunately my problem still continues.
here is the information from the postfix_config_file :
See /usr/share/postfix/main.cf.dist for a commented, more complete version
Debian specific: Specifying a file name will cause the first
line of that file to be used as the name. The Debian default
is /etc/mailname.
#myorigin = /etc/mailname
smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no
appending .domain is the MUA's job.
append_dot_mydomain = no
Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h
readme_directory = no
fresh installs.
compatibility_level = 3.6
TLS parameters
#smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
#smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
smtpd_tls_security_level = may
smtp_tls_CApath=/etc/ssl/certs
smtp_tls_security_level = may
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
myhostname = ip-172-31-0-172.ec2.internal
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
mydestination =
relayhost =
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_command = procmail -a "$EXTENSION"
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
inet_protocols = all
virtual_mailbox_domains = sqlite:/etc/postfix/sqlite_virtual_domains_maps.cf
virtual_alias_maps = sqlite:/etc/postfix/sqlite_virtual_alias_maps.cf, sqlite:/etc/postfix/sqlite_virtual_alias_domain_maps.cf, sqlite:/etc/postfix/sqlite_virtual_alias_domain_catchall_maps.cf
virtual_mailbox_maps = sqlite:/etc/postfix/sqlite_virtual_mailbox_maps.cf, sqlite:/etc/postfix/sqlite_virtual_alias_domain_mailbox_maps.cf
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth
smtpd_sasl_auth_enable = yes
smtpd_recipient_restrictions = permit_sasl_authenticated, permit_mynetworks, reject_unauth_destination
smtpd_use_tls = yes
virtual_transport = lmtp:unix:private/dovecot-lmtp
smtpd_milters = inet:127.0.0.1:11332
non_smtpd_milters = inet:127.0.0.1:11332
milter_mail_macros = i {mail_addr} {client_addr} {client_name} {auth_authen}
milter_protocol = 6
milter_default_action = accept
message_size_limit = 102400000
smtpd_tls_chain_files = /www/server/panel/plugin/mail_sys/cert/guelichwebboost.xyz/privkey.pem,/www/server/panel/plugin/mail_sys/cert/guelichwebboost.xyz/fullchain.pem
tls_server_sni_maps = hash:/etc/postfix/vmail_ssl.map
I have launched the verification
openssl s_client -connect mail.135mailtest.com:465 -starttls smtp
here is the result 
pourtant sur mon wordpress, j'ai toujours le mm problème : 
--------------------------------- FULL ERROR LOG
Versions:
WordPress: 6.1.1
WordPress MS: No
PHP: 7.4.33
WP Mail SMTP: 3.6.1
Params:
Mailer: smtp
Constants: No
ErrorInfo: SMTP Error: Could not connect to SMTP host. Failed to connect to serverSMTP server error: Failed to connect to server
Host: mail.guelichwebboost.xyz
Port: 465
SMTPSecure: ssl
SMTPAutoTLS: bool(true)
SMTPAuth: bool(true)
Server:
OpenSSL: OpenSSL 1.0.2u 20 Dec 2019
Debug:
Email Source: WP Mail SMTP Pro
Mailer: Autre SMTP
SMTP Error: Could not connect to SMTP host. Failed to connect to serverSMTP server error: Failed to connect to server
SMTP Debug:
2022-11-23 10:19:21 Connection: opening to ssl://mail.guelichwebboost.xyz:465, timeout=300, options=array()
2022-11-23 10:19:21 Connection failed. Error #2: stream_socket_client(): SSL operation failed with code 1. OpenSSL Error messages:error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol [/www/wwwroot/form.guelichwebboost.xyz/wp-includes/PHPMailer/SMTP.php line 389]
2022-11-23 10:19:21 Connection failed. Error #2: stream_socket_client(): Failed to enable crypto [/www/wwwroot/form.guelichwebboost.xyz/wp-includes/PHPMailer/SMTP.php line 389]
2022-11-23 10:19:21 Connection failed. Error #2: stream_socket_client(): unable to connect to ssl://mail.guelichwebboost.xyz:465 (Unknown error) [/www/wwwroot/form.guelichwebboost.xyz/wp-includes/PHPMailer/SMTP.php line 389]
2022-11-23 10:19:21 SMTP ERROR: Failed to connect to server: (0)
SMTP Error: Could not connect to SMTP host. Failed to connect to server
