Login failed for root from 190.20.86.0. AUTHENTICATION PLAIN: * BYE. Internal...

[kenygamer]

Introduction

I have been dealing for over 12 hours looking with an issue with my Roundcube installation in my VPS, Ubuntu 16.04. The IMAP server (dovecot) and SMTP server are working and can telnet without connection refused errors.

Issue

However, when I go to my webmail and try to login with username root and the relevant SSH/SFTP password (in order to test if it is working, then I will create additional email addresses), it returns the following error:

IMAP Error in /usr/share/nginx/roundcubemail/program/lib/Roundcube/rcube_imap.php (193): Login failed for root from 190.20.86.0. AUTHENTICATE PLAIN: * BYE. Internal error ocurred. Refer to server log for more information
Logs

The /var/log/nginx/mail.log and the /var/log/nginx/roundcube.error are empty

Configs

Roundcube RC_PATH/config/config.inc.php:

<?php

/* Local configuration for Roundcube Webmail */

// ----------------------------------
// SQL DATABASE
// ----------------------------------
// Database connection string (DSN) for read+write operations
// Format (compatible with PEAR MDB2): db_provider://user:password@host/database
// Currently supported db_providers: mysql, pgsql, sqlite, mssql, sqlsrv, oracle
// For examples see http://pear.php.net/manual/en/package.database.mdb2.intro-dsn.php
// NOTE: for SQLite use absolute path (Linux): 'sqlite:////full/path/to/sqlite.db?mode=0646'
//       or (Windows): 'sqlite:///C:/full/path/to/sqlite.db'
$config['db_dsnw'] = 'mysql://roundcubeuser:XXXXXXXXXXXX@localhost/roundcubemail';

// ----------------------------------
// IMAP
// ----------------------------------
// The mail host chosen to perform the log-in.
// Leave blank to show a textbox at login, give a list of hosts
// to display a pulldown menu or set one host as string.
// To use SSL/TLS connection, enter hostname with prefix ssl:// or tls://
// Supported replacement variables:
// %n - hostname ($_SERVER['SERVER_NAME'])
// %t - hostname without the first part
// %d - domain (http hostname $_SERVER['HTTP_HOST'] without the first part)
// %s - domain name after the '@' from e-mail address provided at login screen
// For example %n = mail.domain.tld, %t = domain.tld
// WARNING: After hostname change update of mail_host column in users table is
//          required to match old user data records with the new host.
$config['default_host'] = 'imaps://mail.domain.com&#039;;

// TCP port used for IMAP connections
$config['default_port'] = 993;

// ----------------------------------
// SMTP
// ----------------------------------
// SMTP server host (for sending mails).
// To use SSL/TLS connection, enter hostname with prefix ssl:// or tls://
// If left blank, the PHP mail() function is used
// Supported replacement variables:
// %h - user's IMAP hostname
// %n - hostname ($_SERVER['SERVER_NAME'])
// %t - hostname without the first part
// %d - domain (http hostname $_SERVER['HTTP_HOST'] without the first part)
// %z - IMAP domain (IMAP hostname without the first part)
// For example %n = mail.domain.tld, %t = domain.tld
$config['smtp_server'] = 'tls://mail.domain.com&#039;;
$config['imap_auth_type'] = 'PLAIN';

// SMTP port (default is 25; use 587 for STARTTLS or 465 for the
// deprecated SSL over SMTP (aka SMTPS))
$config['smtp_port'] = 587;

// SMTP username (if required) if you use %u as the username Roundcube
// will use the current username for login
$config['smtp_user'] = '%u';

// SMTP password (if required) if you use %p as the password Roundcube
// will use the current user's password for login
$config['smtp_pass'] = '%p';

// provide an URL where a user can get support for this Roundcube installation
// PLEASE DO NOT LINK TO THE ROUNDCUBE.NET WEBSITE HERE!
$config['support_url'] = '';

// This key is used for encrypting purposes, like storing of imap password
// in the session. For historical reasons it's called DES_key, but it's used
// with any configured cipher_method (see below).
$config['des_key'] = 'XXXXXXXXXXXXXXXX';

// Name your service. This is displayed on the login screen and in the window title
$config['product_name'] = 'Webmail';

// ----------------------------------
// PLUGINS
// ----------------------------------
// List of active plugins (in plugins/ directory)
$config['plugins'] = array();

$config['debug_level'] = 4; //to debug the php authentication failed error
How do I solve this issue while trying to login? I am very worried about the amount of emails I have losed with this 24-hour downtime (20+).

Thanks for your answers.

[SKaero]

That error message is coming from from your mail server so you need to check your mail server logs.

[kenygamer]

Where are these logs files located on? Thanks.

[SKaero]

https://wiki2.dovecot.org/Logging

[kenygamer]

The log /var/log/syslog says:
Nov 28 09:31:17 mail systemd[1]: Starting Daily apt download activities...
Nov 28 09:31:25 mail systemd[1]: Started Daily apt download activities.
Nov 28 09:39:01 mail CRON[29000]: (root) CMD (  [ -x /usr/lib/php/sessionclean ] && /usr/lib/php/sessionclean)
Nov 28 10:09:01 mail CRON[29414]: (root) CMD (  [ -x /usr/lib/php/sessionclean ] && /usr/lib/php/sessionclean)
Nov 28 10:17:01 mail CRON[29553]: (root) CMD (   cd / && run-parts --report /etc/cron.hourly)
Nov 28 10:39:01 mail CRON[29743]: (root) CMD (  [ -x /usr/lib/php/sessionclean ] && /usr/lib/php/sessionclean)
Nov 28 10:54:55 mail systemd[1]: Started Session 159 of user root.
Nov 28 10:55:00 mail dovecot: doveadm: Debug: This is Dovecot's debug log (1511866500)
Nov 28 10:55:00 mail dovecot: doveadm: This is Dovecot's info log (1511866500)
Nov 28 10:55:00 mail dovecot: doveadm: Warning: This is Dovecot's warning log (1511866500)
Nov 28 10:55:00 mail dovecot: doveadm: Error: This is Dovecot's error log (1511866500)
Nov 28 10:55:00 mail dovecot: doveadm: Fatal: This is Dovecot's fatal log (1511866500)
Nov 28 10:55:08 mail systemd[1]: Started Session 160 of user root.

[kenygamer]

FOLLOW UP
New lines appeared in the Dovecot error log after repeating the login to roundcube:


Nov 28 10:57:31 mail dovecot: imap-login: Login: user=<root>, method=PLAIN, rip=::1, lip=::1, mpid=30111, TLS, session=<myyv4ghf5JAAAAAAAAAAAAAAAAAAAAAB>
Nov 28 10:57:31 mail dovecot: imap(root): Error: Invalid settings in userdb: userdb returned 0 as uid
Nov 28 10:57:31 mail dovecot: imap(root): Error: Invalid user settings. Refer to server log for more information.

[SKaero]

Dovecot can't find the user, its possible Dovecot also disallowing login for root.

[kenygamer]

Yes, I can't get it. I want to use [email protected], not [email protected]. What do I have to do in CLI to get a new system user called me so that this can look like [email protected]?

[SKaero]

You'll need to create a new mail account, that all depends on how your mail server is setup. You'll most likely get a better response on forum for either your mail server or server control panel if your using one since your question isn't Roundcube specific.

[kenygamer]

Hello there, I don't use ISPConfig or that. I only use postfix and dovecot all installed with apt-get on Ubuntu with SSL/TLS already setted up