dovecot - Nov 2021 - dovecot Error: Failed to establish relay connection: Failed to connect to remote server

# doveconf -n
# 2.3.7.2 (3c910f64b): /etc/dovecot/dovecot.conf
# Pigeonhole version 0.5.7.2 ()
# OS: Linux 5.14.17-x86_64-linode150 x86_64 Ubuntu 20.04.3 LTS
# Hostname: mail.servicemouse.com
auth_verbose = yes
mail_privileged_group = mail
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
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
}
plugin {
  sieve = file:~/sieve;active=~/.dovecot.sieve
}
protocols = " imap lmtp sieve pop3 submission"
service auth {
  unix_listener /var/spool/postfix/private/auth {
    group = postfix
    mode = 0660
    user = postfix
  }
}
ssl_cert = </etc/letsencrypt/live/mail.servicemouse.com/fullchain.pem
ssl_client_ca_dir = /etc/letsencrypt/live/mail.servicemouse.com
ssl_dh = # hidden, use -P to show it
ssl_key = # hidden, use -P to show it
submission_relay_host = 127.0.0.1
submission_relay_ssl = starttls
submission_relay_trusted = yes
userdb {
  driver = passwd
}

Am 27.11.2021 um 07:34 schrieb fugee ohu:
> submission_relay_host = 127.0.0.1
> submission_relay_ssl = starttls
> submission_relay_trusted = yes
Make sure your MTA listens on localhost port 25 offering STARTTLS.

See https://doc.dovecot.org/admin_manual/submission_server/

Alexander