Hey there,
sorry for taking me so long!
Sure: Here is dovecot/dovecot.log
Nov 4 19:22:04 mail dovecot: master: Dovecot v2.2.27 (c0f36b0) starting up for pop3, imap, sieve, lmtp (core dumps disabled)
Nov 4 19:22:05 mail dovecot: ssl-params: Warning: Regenerating /var/lib/dovecot/ssl-parameters.dat for ssl_dh_parameters_length=2048
Nov 4 19:22:05 mail dovecot: ssl-params: Generating SSL parameters
Nov 4 19:22:26 mail dovecot: ssl-params: SSL parameters regeneration completed
Nov 4 20:01:57 mail dovecot: auth-worker(4153): Warning: mysql: Query failed, retrying: Unknown column 'allow_nets' in 'field list'
Nov 4 20:01:57 mail dovecot: auth-worker(4153): Error: sql(mail@adress.net,127.0.0.1,<wSr52ixd/L5/AAAB>): Password query failed: Unknown column 'allow_nets' in 'field list'
Nov 4 20:02:08 mail dovecot: auth-worker(4153): Warning: mysql: Query failed, retrying: Unknown column 'allow_nets' in 'field list'
Nov 4 20:02:08 mail dovecot: auth-worker(4153): Error: sql(mail@adress.net,127.0.0.1,<dy5q2yxdGL9/AAAB>): Password query failed: Unknown column 'allow_nets' in 'field list'
Nov 4 20:02:17 mail dovecot: auth-worker(4153): Warning: mysql: Query failed, retrying: Unknown column 'allow_nets' in 'field list'
Nov 4 20:02:17 mail dovecot: auth-worker(4153): Error: sql(mail@adress.net,127.0.0.1,<NGAs3CxdJL9/AAAB>): Password query failed: Unknown column 'allow_nets' in 'field list'
Nov 4 20:16:08 mail dovecot: master: Dovecot v2.2.27 (c0f36b0) starting up for pop3, imap, sieve, lmtp (core dumps disabled)
Nov 4 20:17:04 mail dovecot: auth-worker(1044): Warning: mysql: Query failed, retrying: Unknown column 'allow_nets' in 'field list'
Nov 4 20:17:04 mail dovecot: auth-worker(1044): Error: sql(mail@adress.net,62.143.189.200,<8vcMES1dstI+j73I>): Password query failed: Unknown column 'allow_nets' in 'field list'
Nov 4 20:17:08 mail dovecot: auth-worker(1044): Warning: mysql: Query failed, retrying: Unknown column 'allow_nets' in 'field list'
Nov 4 20:17:08 mail dovecot: auth-worker(1044): Error: sql(mailinglist@stephan-schaffner.de,62.143.189.200,<w6kTES1dsdI+j73I>): Password query failed: Unknown column 'allow_nets' in 'field list'
Nov 4 20:17:09 mail dovecot: auth-worker(1044): Warning: mysql: Query failed, retrying: Unknown column 'allow_nets' in 'field list'
Nov 4 20:17:09 mail dovecot: auth-worker(1044): Error: sql(mail@adress.net,62.143.189.200,<kfwYES1dsNI+j73I>): Password query failed: Unknown column 'allow_nets' in 'field list'
Nov 4 20:17:09 mail dovecot: auth-worker(1044): Warning: mysql: Query failed, retrying: Unknown column 'allow_nets' in 'field list'
Nov 4 20:17:09 mail dovecot: auth-worker(1044): Error: sql(mail@adress.net,62.143.189.200,<7sUdES1dr9I+j73I>): Password query failed: Unknown column 'allow_nets' in 'field list'
Nov 4 20:17:09 mail dovecot: auth-worker(1044): Warning: mysql: Query failed, retrying: Unknown column 'allow_nets' in 'field list'
Nov 4 20:17:09 mail dovecot: auth-worker(1044): Error: sql(mail@adress.net,62.143.189.200,<w0cjES1dqNI+j73I>): Password query failed: Unknown column 'allow_nets' in 'field list'
Nov 4 20:17:49 mail dovecot: auth-worker(1044): Warning: mysql: Query failed, retrying: Unknown column 'allow_nets' in 'field list'
Nov 4 20:17:49 mail dovecot: auth-worker(1044): Error: sql(mail@adress.net,62.143.189.200,<8vcMES1dstI+j73I>): Password query failed: Unknown column 'allow_nets' in 'field list'
Nov 4 20:18:00 mail dovecot: auth-worker(1044): Warning: mysql: Query failed, retrying: Unknown column 'allow_nets' in 'field list'
Nov 4 20:18:00 mail dovecot: auth-worker(1044): Error: sql(mail@adress.net,62.143.189.200,<8vcMES1dstI+j73I>): Password query failed: Unknown column 'allow_nets' in 'field list'
Nov 4 20:18:06 mail dovecot: auth-worker(1044): Warning: mysql: Query failed, retrying: Unknown column 'allow_nets' in 'field list'
Nov 4 20:18:06 mail dovecot: auth-worker(1044): Error: sql(mail@adress.net,62.143.189.200,<8vcMES1dstI+j73I>): Password query failed: Unknown column 'allow_nets' in 'field list'
Nov 4 20:18:59 mail dovecot: auth-worker(1044): Warning: mysql: Query failed, retrying: Unknown column 'allow_nets' in 'field list'
Nov 4 20:18:59 mail dovecot: auth-worker(1044): Error: sql(mail@adress.net,127.0.0.1,<dXfmFy1d8Jp/AAAB>): Password query failed: Unknown column 'allow_nets' in 'field list'
Nov 6 21:15:56 mail dovecot: master: Dovecot v2.2.27 (c0f36b0) starting up for pop3, imap, sieve, lmtp (core dumps disabled)
Nov 6 21:16:10 mail dovecot: auth-worker(1206): Warning: mysql: Query failed, retrying: Unknown column 'allow_nets' in 'field list'
Nov 6 21:16:10 mail dovecot: auth-worker(1206): Error: sql(mail@adress.net,127.0.0.1,<lFwcIFZd7IV/AAAB>): Password query failed: Unknown column 'allow_nets' in 'field list'
and here we got /var/log/mail.log:
Nov 4 20:01:59 mail roundcube: <ej4snsuh> IMAP Error: Login failed for mail@adress.net from 192.168.0.2. LOGIN: Temporary authentication failure. [mail:2017-11-04 19:01:59] in /opt/www/roundcubemail-1.3.0/program/lib/Roundcube/rcube_imap.php on line 196 (POST /mail/?_task=login&_action=login)
Nov 4 20:01:59 mail roundcube: <ej4snsuh> DB Error: [1054] Unknown column 'failed_login' in 'field list' (SQL Query: UPDATE `users` SET `failed_login` = '2017-11-04 20:01:59', `failed_login_counter` = 1 WHERE `user_id` = '4') in /opt/www/roundcubemail-1.3.0/program/lib/Roundcube/rcube_db.php on line 542 (POST /mail/?_task=login&_action=login)
Nov 4 20:02:02 mail postfix/pickup[911]: 5719840D13: uid=0 from=<root>
Nov 4 20:02:02 mail postfix/cleanup[4172]: 5719840D13: message-id=<20171104190202.5719840D13@mail.server.net>
Nov 4 20:02:02 mail postfix/qmgr[912]: 5719840D13: from=<root@mail.server.net>, size=1504, nrcpt=1 (queue active)
Nov 4 20:02:10 mail roundcube: <ej4snsuh> IMAP Error: Login failed for mail@adress.net from 192.168.0.2. LOGIN: Temporary authentication failure. [mail:2017-11-04 19:02:10] in /opt/www/roundcubemail-1.3.0/program/lib/Roundcube/rcube_imap.php on line 196 (POST /mail/?_task=login&_action=login)
Nov 4 20:02:10 mail roundcube: <ej4snsuh> DB Error: [1054] Unknown column 'failed_login' in 'field list' (SQL Query: UPDATE `users` SET `failed_login` = '2017-11-04 20:02:10', `failed_login_counter` = 1 WHERE `user_id` = '4') in /opt/www/roundcubemail-1.3.0/program/lib/Roundcube/rcube_db.php on line 542 (POST /mail/?_task=login&_action=login)
Nov 4 20:02:12 mail postfix/10025/smtpd[4190]: connect from localhost[127.0.0.1]
Nov 4 20:02:12 mail postfix/10025/smtpd[4190]: A7ABE40D1C: client=localhost[127.0.0.1]
Nov 4 20:02:12 mail postfix/cleanup[4172]: A7ABE40D1C: message-id=<20171104190202.5719840D13@mail.server.net>
Nov 4 20:02:12 mail postfix/10025/smtpd[4190]: disconnect from localhost[127.0.0.1] ehlo=1 mail=1 rcpt=1 data=1 quit=1 commands=5
Nov 4 20:02:12 mail postfix/qmgr[912]: A7ABE40D1C: from=<root@mail.server.net>, size=2008, nrcpt=1 (queue active)
Nov 4 20:02:12 mail amavis[1014]: (01014-01) Passed CLEAN {RelayedInbound}, [127.0.0.1] <root@mail.server.net> -> <root@mail.server.net>, Message-ID: <20171104190202.5719840D13@mail.server.net>, mail_id: W79a_-r8_5QW, Hits: 0.001, size: 1504, queued_as: A7ABE40D1C, 10300 ms, Tests: [NO_RELAYS=-0.001,TVD_SPACE_RATIO=0.001,URIBL_BLOCKED=0.001]
Nov 4 20:02:12 mail postfix/amavis/smtp[4183]: 5719840D13: to=<root@mail.server.net>, relay=127.0.0.1[127.0.0.1]:10024, delay=10, delays=0.12/0.03/0/10, dsn=2.0.0, status=sent (250 2.0.0 from MTA(smtp:[127.0.0.1]:10025): 250 2.0.0 Ok: queued as A7ABE40D1C)
Nov 4 20:02:12 mail postfix/qmgr[912]: 5719840D13: removed
Nov 4 20:02:12 mail postfix/cleanup[4172]: BA06E40D13: message-id=<20171104190202.5719840D13@mail.server.net>
Nov 4 20:02:12 mail postfix/local[4192]: A7ABE40D1C: to=<root@mail.server.net>, relay=local, delay=0.08, delays=0.02/0.05/0/0.01, dsn=2.0.0, status=sent (forwarded as BA06E40D13)
Nov 4 20:02:12 mail postfix/qmgr[912]: BA06E40D13: from=<root@mail.server.net>, size=2151, nrcpt=1 (queue active)
Nov 4 20:02:12 mail postfix/qmgr[912]: A7ABE40D1C: removed
Nov 4 20:02:12 mail postfix/pipe[4194]: BA06E40D13: to=<postmaster@klopperhoppel.de>, relay=dovecot, delay=0.14, delays=0.01/0.02/0/0.12, dsn=2.0.0, status=sent (delivered via dovecot service)
Nov 4 20:02:12 mail postfix/qmgr[912]: BA06E40D13: removed
Nov 4 20:02:19 mail roundcube: <ej4snsuh> IMAP Error: Login failed for mail@adress.netfrom 192.168.0.2. LOGIN: Temporary authentication failure. [mail:2017-11-04 19:02:19] in /opt/www/roundcubemail-1.3.0/program/lib/Roundcube/rcube_imap.php on line 196 (POST /mail/?_task=login&_action=login)
Nov 4 20:02:19 mail roundcube: <ej4snsuh> DB Error: [1054] Unknown column 'failed_login' in 'field list' (SQL Query: UPDATE `users` SET `failed_login` = '2017-11-04 20:02:19', `failed_login_counter` = 1 WHERE `user_id` = '2') in /opt/www/roundcubemail-1.3.0/program/lib/Roundcube/rcube_db.php on line 542 (POST /mail/?_task=login&_action=login)
Nov 4 20:16:10 mail postfix/postfix-script[863]: starting the Postfix mail system
Nov 4 20:16:10 mail postfix/master[865]: daemon started -- version 3.1.6, configuration /etc/postfix
That are the errors I found