I have a postfix mail server that works perfectly, but when I try to connect it with Thunderbird it gives me this error
Fatal: master: service(imap): child 102561 killed with signal 6 (core dumped)
Here are the configuration files
main.cf
smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no
append_dot_mydomain = no
readme_directory = no
compatibility_level = 2
smtpd_use_tls = yes
smtpd_tls_cert_file=/etc/letsencrypt/live/mail.mastad.pl/fullchain.pem
smtpd_tls_key_file=/etc/letsencrypt/live/mail.mastad.pl/privkey.pem
smtpd_tls_security_level=may
smtp_tls_CApath=/etc/letsencrypt/live/mail.mastad.pl/
smtp_tls_security_level=may
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
myhostname = mastad
mydomain = mastad.pl
mail_spool_directory = /media/mail
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
mydestination = $myhostname localhost.$mydomain localhost $mydomain
relayhost =
mynetworks = 127.0.0.0/12 172.31.1.1
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
inet_protocols = all
home-mailbox = /media/mail
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth
smtpd_sasl_local-domain =
smtpd_sasl_security-options = noanonymous,noplaintext
smtpd_sasl_tls-security-options = noanonymous
broken_sasl_auth_clients = yes
smtpd_sasl_auth_enable = yes
smtp_tls_note_starttls_offer = yes
smtpd_tls_loglevel = 1
smtpd_tls_received_header = yes
smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3, !TLSv1, !TLSv1.1 TLSv1.2
smtpd_tls_protocols = !SSLv2, !SSLv3, !TLSv1, !TLSv1.1, TLSv1.2
virtual_mailbox_domains = mail.mastad.pl
10-ssl.conf:
ssl = yes
ssl_cert = </etc/letsencrypt/live/mail.mastad.pl/fullchain.pem
ssl_key = </etc/letsencrypt/live/mail.mastad.pl/privkey.pem
ssl_cipher_list = ALL:!LOW:!SSLv2:!EXP:!aNULL
ssl_client_ca_dir = /etc/letsencrypt/live/mail.mastad.pl/
ssl_dh = </usr/share/dovecot/dh.pem