Zertifikatproblem

[Dr. Martin Mandelkow]

Hallo!

Ich habe einen neuen Mailserver mit Postfix + Dovecot aufgesetzt
(CentOS 8).
Die Konfiguration habe ich von meinem alten Server (CentOS 6) übernommen.

Jetzt verbindet sich meine Android-App (K-9 Mail) nicht mehr per IMAP.
Thunderbird funktioniert.

Wo ist der Fehler?



[root at localhost ~]# dovecot --version
2.3.8 (9df20d2db)

[root at localhost ~]# doveconf -n
# 2.3.8 (9df20d2db): /etc/dovecot/dovecot.conf
# Pigeonhole version 0.5.8 (b7b03ba2)
# OS: Linux 4.18.0-193.6.3.el8_2.x86_64 x86_64 CentOS Linux release
8.2.2004 (Core)
# Hostname: localhost
auth_debug = yes
auth_debug_passwords = yes
auth_mechanisms = cram-md5 plain login
auth_verbose = yes
auth_verbose_passwords = sha1
first_valid_uid = 1000
mail_debug = yes
mail_location = maildir:~/Maildir
managesieve_notify_capability = mailto
managesieve_sieve_capability = fileinto reject envelope
encoded-character vacation subaddress comparator-i;ascii-numeric
relational regex imap4flags copy include variables body enotify
environment mailbox date index ihave duplicate mime foreverypart
extracttext
mbox_write_locks = fcntl
namespace inbox {
  inbox = yes
  location =
  mailbox Drafts {
    special_use = \Drafts
  }
  mailbox Junk {
    special_use = \Junk
  }
  mailbox Sent {
    special_use = \Sent
  }
  mailbox "Sent Messages" {
    special_use = \Sent
  }
  mailbox Trash {
    special_use = \Trash
  }
  prefix =
}
passdb {
  driver = pam
}
passdb {
  args = scheme=CRYPT username_format=%u /etc/dovecot/users
  driver = passwd-file
}
plugin {
  sieve = ~/.dovecot.sieve
  sieve_dir = ~/sieve
  sieve_global_dir = /etc/dovecot/sieve/global/
  sieve_global_path = /etc/dovecot/sieve/default.sieve
}
protocols = imap sieve lmtp sieve
service auth {
  unix_listener /var/spool/postfix/private/auth {
    group = postfix
    mode = 0666
    user = postfix
  }
}
service lmtp {
  unix_listener /var/spool/postfix/private/dovecot-lmtp {
    group = postfix
    mode = 0600
    user = postfix
  }
}
service managesieve-login {
  inet_listener sieve {
    port = 4190
  }
}
ssl_cert = </etc/pki/tls/certs/certificate.cer
ssl_key = # hidden, use -P to show it
userdb {
  driver = passwd
}
userdb {
  args = username_format=%u /etc/dovecot/users
  driver = passwd-file
}
verbose_ssl = yes
protocol lmtp {
  auth_username_format = %n
  mail_plugins = " quota sieve"
  postmaster_address = postmaster at xxx.de
}
protocol sieve {
  managesieve_max_line_length = 65536
}