diff --git a/ChangeLog b/ChangeLog
index ca7864fc..ec8bdda3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -27,6 +27,8 @@ releases.
 * Monit config: scripting is not supported in path (gh-1556)
 * `filter.d/asterisk.conf`
     - Fixed to match different asterisk log prefix (source file: method:)
+* `filter.d/dovecot.conf`
+    - Fixed failregex ignores failures through some not relevant info (gh-1623)
 * `filter.d/ignorecommands/apache-fakegooglebot`
     - Fixed error within apache-fakegooglebot, that will be called 
       with wrong python version (gh-1506)
diff --git a/THANKS b/THANKS
index 64de43a4..7d9137d7 100644
--- a/THANKS
+++ b/THANKS
@@ -119,6 +119,7 @@ Thomas Mayer
 Tom Pike
 Tom Hendrikx
 Tomas Pihl
+Thomas Skierlo (phaleas)
 Tony Lawrence
 Tomasz Ciolek
 Tyler
diff --git a/config/filter.d/dovecot.conf b/config/filter.d/dovecot.conf
index 136a3947..a3dc60bb 100644
--- a/config/filter.d/dovecot.conf
+++ b/config/filter.d/dovecot.conf
@@ -9,11 +9,11 @@ before = common.conf
 
 _daemon = (auth|dovecot(-auth)?|auth-worker)
 
-failregex = ^%(__prefix_line)s(%(__pam_auth)s(\(dovecot:auth\))?:)?\s+authentication failure; logname=\S* uid=\S* euid=\S* tty=dovecot ruser=\S* rhost=<HOST>(\s+user=\S*)?\s*$
-            ^%(__prefix_line)s(pop3|imap)-login: (Info: )?(Aborted login|Disconnected)(: Inactivity)? \(((auth failed, \d+ attempts)( in \d+ secs)?|tried to use (disabled|disallowed) \S+ auth)\):( user=<\S*>,)?( method=\S+,)? rip=<HOST>(, lip=(\d{1,3}\.){3}\d{1,3})?(, TLS( handshaking(: SSL_accept\(\) failed: error:[\dA-F]+:SSL routines:[TLS\d]+_GET_CLIENT_HELLO:unknown protocol)?)?(: Disconnected)?)?(, session=<\S+>)?\s*$
-            ^%(__prefix_line)s(Info|dovecot: auth\(default\)|auth-worker\(\d+\)): pam\(\S+,<HOST>\): pam_authenticate\(\) failed: (User not known to the underlying authentication module: \d+ Time\(s\)|Authentication failure \(password mismatch\?\))\s*$
-            ^%(__prefix_line)s(auth|auth-worker\(\d+\)): (pam|passwd-file)\(\S+,<HOST>\): unknown user\s*$
-            ^%(__prefix_line)s(auth|auth-worker\(\d+\)): Info: ldap\(\S*,<HOST>,\S*\): invalid credentials\s*$
+failregex = ^%(__prefix_line)s(?:%(__pam_auth)s(?:\(dovecot:auth\))?:)?\s+authentication failure; logname=\S* uid=\S* euid=\S* tty=dovecot ruser=\S* rhost=<HOST>(?:\s+user=\S*)?\s*$
+            ^%(__prefix_line)s(?:pop3|imap)-login: (?:Info: )?(?:Aborted login|Disconnected)(?::(?: [^ \(]+)+)? \((?:auth failed, \d+ attempts( in \d+ secs)?|tried to use (disabled|disallowed) \S+ auth)\):( user=<[^>]+>,)?( method=\S+,)? rip=<HOST>(?:, lip=\S+)?(?:, TLS(?: handshaking(?:: SSL_accept\(\) failed: error:[\dA-F]+:SSL routines:[TLS\d]+_GET_CLIENT_HELLO:unknown protocol)?)?(: Disconnected)?)?(, session=<\S+>)?\s*$
+            ^%(__prefix_line)s(?:Info|dovecot: auth\(default\)|auth-worker\(\d+\)): pam\(\S+,<HOST>\): pam_authenticate\(\) failed: (User not known to the underlying authentication module: \d+ Time\(s\)|Authentication failure \(password mismatch\?\))\s*$
+            ^%(__prefix_line)s(?:auth|auth-worker\(\d+\)): (?:pam|passwd-file)\(\S+,<HOST>\): unknown user\s*$
+            ^%(__prefix_line)s(?:auth|auth-worker\(\d+\)): Info: ldap\(\S*,<HOST>,\S*\): invalid credentials\s*$
 
 ignoreregex = 
 
@@ -30,3 +30,4 @@ journalmatch = _SYSTEMD_UNIT=dovecot.service
 # Author: Martin Waschbuesch
 #         Daniel Black (rewrote with begin and end anchors)
 #         Martin O'Neal (added LDAP authentication failure regex)
+#         Sergey G. Brester aka sebres (reviewed, optimized, IPv6-compatibility)
diff --git a/fail2ban/tests/files/logs/dovecot b/fail2ban/tests/files/logs/dovecot
index 627b8dc8..987f89f1 100644
--- a/fail2ban/tests/files/logs/dovecot
+++ b/fail2ban/tests/files/logs/dovecot
@@ -73,3 +73,8 @@ Jul 02 13:49:32 hostname dovecot[442]: pop3-login: Disconnected (no auth attempt
 
 # failJSON: { "time": "2005-03-23T06:10:52", "match": true , "host": "52.37.139.121" }
 Mar 23 06:10:52 auth: Info: ldap(dog,52.37.139.121,): invalid credentials
+
+# failJSON: { "time": "2005-07-26T11:11:21", "match": true , "host": "192.0.2.1" }
+Jul 26 11:11:21 hostname dovecot: imap-login: Disconnected: Too many invalid commands (tried to use disallowed plaintext auth): user=<test>, rip=192.0.2.1, lip=192.168.1.1, session=<S5dIdTFCDKUWWMbU>
+# failJSON: { "time": "2005-07-26T11:12:19", "match": true , "host": "192.0.2.2" }
+Jul 26 11:12:19 hostname dovecot: imap-login: Disconnected: Too many invalid commands (auth failed, 1 attempts in 17 secs): user=<test>, method=PLAIN, rip=192.0.2.2, lip=192.168.1.1, TLS, session=<g3ZKeDECFqlWWMbU>