Issue Postfix: SSL_accept error

[Clearasil]

Your operating system ‪Ubuntu 14.04.4 LTS‬
Your current used Plesk- Product 12.5.30 Update #44 ,
Your depending installed mail - server software postfix

I cannot send mail using my server, webmail works fine, receiving mail on Thunderbird works fine as well.

When I try to send mail in Thunderbird, this appears in my maillog:

Aug 20 17:59:46 vps-248826-4222 postfix/smtpd[9411]: SSL_accept error from 5ED46C33.cm-7-5b.dynamic.ziggo.nl[94.212.108.51]: 0
Aug 20 17:59:46 vps-248826-4222 postfix/smtpd[9411]: warning: TLS library problem: error:14094418:SSL routines:SSL3_READ_BYTES:tlsv1 alert unknown ca:s3_pkt.c:1262:SSL alert number 48:
Aug 20 17:59:46 vps-248826-4222 postfix/smtpd[9411]: lost connection after STARTTLS from 5ED46C33.cm-7-5b.dynamic.ziggo.nl[94.212.108.51]
Aug 20 17:59:46 vps-248826-4222 postfix/smtpd[9411]: disconnect from 5ED46C33.cm-7-5b.dynamic.ziggo.nl[94.212.108.51]

My main.cf:

# 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

# TLS parameters
smtpd_tls_cert_file = /etc/postfix/tls/smtpd.pem
smtpd_tls_key_file = /etc/postfix/tls/smtpd.pem
smtpd_use_tls = yes
smtpd_tls_session_cache_database = btree:${queue_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${queue_directory}/smtp_scache

# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.

smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
myhostname = derkvanderheide.nl
alias_maps = hash:/etc/aliases, hash:/var/spool/postfix/plesk/aliases
alias_database = hash:/etc/aliases
mydestination = localdomain, localhost, localhost.localdomain, localhost
relayhost =
mynetworks =
mailbox_command =
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
inet_protocols = all
virtual_mailbox_domains = $virtual_mailbox_maps, hash:/var/spool/postfix/plesk/virtual_domains
virtual_alias_maps = $virtual_maps, hash:/var/spool/postfix/plesk/virtual
virtual_mailbox_maps = , hash:/var/spool/postfix/plesk/vmailbox
transport_maps = , hash:/var/spool/postfix/plesk/transport
smtpd_tls_security_level = may
smtp_tls_security_level = may
smtp_use_tls = yes
smtpd_timeout = 3600s
smtpd_proxy_timeout = 3600s
disable_vrfy_command = yes
smtpd_sender_restrictions = check_sender_access hash:/var/spool/postfix/plesk/blacklists, permit_sasl_authenticated
smtpd_client_restrictions = permit_mynetworks, permit_sasl_authenticated
smtp_send_xforward_command = yes
smtpd_authorized_xforward_hosts = 127.0.0.0/8 [::1]/128
smtpd_sasl_auth_enable = yes
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
virtual_mailbox_base = /var/qmail/mailnames
virtual_uid_maps = static:30
virtual_gid_maps = static:31
smtpd_milters = , inet:127.0.0.1:12768
sender_dependent_default_transport_maps = hash:/var/spool/postfix/plesk/sdd_transport_maps
virtual_transport = plesk_virtual
plesk_virtual_destination_recipient_limit = 1
mailman_destination_recipient_limit = 1
virtual_mailbox_limit = 0
smtpd_tls_mandatory_protocols = TLSv1 TLSv1.1 TLSv1.2
smtpd_tls_protocols = TLSv1 TLSv1.1 TLSv1.2
smtpd_tls_ciphers = medium
smtpd_tls_mandatory_ciphers = medium
tls_medium_cipherlist = HIGH:!aNULL:!MD5
message_size_limit = 10240000
smtpd_tls_auth_only = no
smtp_tls_note_starttls_offer = yes
smtpd_tls_CAfile = /etc/postfix/tls/smtpd.pem
smtpd_tls_loglevel = 1
smtpd_tls_received_header = yes
smtpd_tls_session_cache_timeout = 3600s
tls_random_source = dev:/dev/urandom
myorigin = /etc/mailname
home_mailbox = Maildir/
smtpd_sasl_local_domain =
smtpd_sasl_security_options = noanonymous
broken_sasl_auth_clients = yes
smtp_tls_CAfile = /etc/postfix/tls/smtpd.pem
smtp_tls_cert_file = /etc/postfix/tls/smtpd.pem
smtp_tls_key_file = /etc/postfix/tls/smtpd.pem
smtpd_tls_ask_ccert = yes

 

[Lloyd_mcse]

Hi,
I'd try and remove...

smtpd_tls_ask_ccert = yes

Or are clients being verified by certificate?

And...

smtp_tls_CAfile = /etc/postfix/tls/smtpd.pem
smtpd_tls_CAfile = /etc/postfix/tls/smtpd.pem

It's self-signed so I'm not sure why that's there, you don't need them.
Hope that helps.
Kind regards

Lloyd