==== Required information ====
- iRedMail version (check /etc/iredmail-release):
- Linux/BSD distribution name and version:
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):
- Web server (Apache or Nginx):
- Manage mail accounts with iRedAdmin-Pro?
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

May 31 14:43:34 nm2 postfix/smtpd[12077]: warning: TLS library problem: error:1417A0C1:SSL routines:tls_post_process_client_hello:no shared cipher:../ssl/statem/statem_srvr.c:1422:

also getting SSL routines:ssl3_get_client_hello:no shared cipher:s3_srvr.c:1418:

cat /etc/postfix/main.cf | grep tls
# smtpd_tls_cert_file = /etc/ssl/certs/iRedMail_CA.pem
# smtpd_tls_key_file = /etc/ssl/private/iRedMail.key
# smtpd_tls_CAfile = /etc/ssl/certs/iRedMail_CA.pem
smtpd_tls_cert_file = /etc/ssl/certs/nm2.abgnetwork.net.crt
smtpd_tls_key_file = /etc/ssl/private/nm2.key
smtpd_tls_CAfile = /etc/ssl/certs/gd_bundle.crt
smtpd_use_tls=yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
smtpd_tls_protocols = SSLv2, !SSLv3, TLSv1.1, TLSv1.2
smtpd_tls_security_level = may
smtpd_enforce_tls = no
smtpd_tls_loglevel = 0
tls_random_source = dev:/dev/urandom
# tls_daemon_random_source = dev:/dev/urandom
# smtp_pix_workaround_threshold_time = 500ssmtp_tls_security_level = may
smtp_tls_CAfile = $smtpd_tls_CAfile
smtpd_tls_exclude_ciphers = aNULL, eNULL, EXPORT, DES, RC4, MD5, PSK, aECDH, EDH-DSS-DES-CBC3-SHA, EDH-RSA-DES-CDC3-SHA, KRB5-DE5, CBC3-SHA
smtpd_tls_dh1024_param_file = /etc/ssl/dhparams.pem

nm2:/etc/amavis/conf.d# cat /etc/dovecot/dovecot.conf | grep ssl
ssl = yes
verbose_ssl = no
ssl_cipher_list = ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:AES:CAMELLIA:DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA
# ssl_cipher_list = ALL:!ADH:!LOW:!SSLv2:!SSLv3:!EXP:!aNULL:+HIGH:+MEDIUM
# ssl_cert = </etc/ssl/certs/iRedMail_CA.pem
# ssl_key = </etc/ssl/private/iRedMail.key
ssl_cert = </etc/ssl/certs/nm2.abgnetwork.net.pem
ssl_key = </etc/ssl/private/nm2.key
ssl_ca = </etc/ssl/certs/gd_bundle.pem

I tried this in the Dovecot.conf file, but Outlook 2010 stopped working for users.
# ssl_cipher_list = ALL:!ADH:!LOW:!SSLv2:!SSLv3:!EXP:!aNULL:+HIGH:+MEDIUM

nm2:/etc/amavis/conf.d# cat /etc/iredmail-release
0.9.6

Debian

Tried upgrading openssl
Tried upgrading postfix
added smtpd_tls_protocols = SSLv2, !SSLv3, TLSv1.1, TLSv1.2