diff --git a/ChangeLog b/ChangeLog
index 57737828..2a6b5733 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -36,6 +36,8 @@ releases.
     - Allow for having no trailing space after 'failed:' (gh-1497)
 * `filter.d/vsftpd.conf`
     - Optional reason part in message after FAIL LOGIN (gh-1543)
+* `filter.d/sendmail-reject.conf`
+    - removed mandatory double space (if dns-host available, gh-1579)
 
 
 ### New Features
diff --git a/config/filter.d/sendmail-reject.conf b/config/filter.d/sendmail-reject.conf
index 93b8343c..20d3648e 100644
--- a/config/filter.d/sendmail-reject.conf
+++ b/config/filter.d/sendmail-reject.conf
@@ -23,7 +23,7 @@ _daemon = (?:(sm-(mta|acceptingconnections)|sendmail))
 
 failregex = ^%(__prefix_line)s\w{14}: ruleset=check_rcpt, arg1=(?P<email><\S+@\S+>), relay=(\S+ )?\[<HOST>\]( \(may be forged\))?, reject=(550 5\.7\.1 (?P=email)\.\.\. Relaying denied\. (IP name possibly forged \[(\d+\.){3}\d+\]|Proper authentication required\.|IP name lookup failed \[(\d+\.){3}\d+\])|553 5\.1\.8 (?P=email)\.\.\. Domain of sender address \S+ does not exist|550 5\.[71]\.1 (?P=email)\.\.\. (Rejected: .*|User unknown))$
             ^%(__prefix_line)sruleset=check_relay, arg1=(?P<dom>\S+), arg2=<HOST>, relay=((?P=dom) )?\[(\d+\.){3}\d+\]( \(may be forged\))?, reject=421 4\.3\.2 (Connection rate limit exceeded\.|Too many open connections\.)$
-            ^%(__prefix_line)s\w{14}: rejecting commands from  (\S+ )?\[<HOST>\] due to pre-greeting traffic after \d+ seconds$
+            ^%(__prefix_line)s\w{14}: rejecting commands from (\S* )?\[<HOST>\] due to pre-greeting traffic after \d+ seconds$
             ^%(__prefix_line)s\w{14}: (\S+ )?\[<HOST>\]: ((?i)expn|vrfy) \S+ \[rejected\]$
             ^(?P<__prefix>%(__prefix_line)s\w+: )<[^@]+@[^>]+>\.\.\. No such user here<SKIPLINES>(?P=__prefix)from=<[^@]+@[^>]+>, size=\d+, class=\d+, nrcpts=\d+, bodytype=\w+, proto=E?SMTP, daemon=MTA, relay=\S+ \[<HOST>\]$
 
diff --git a/fail2ban/tests/files/logs/sendmail-reject b/fail2ban/tests/files/logs/sendmail-reject
index b326cf43..70d4dde6 100644
--- a/fail2ban/tests/files/logs/sendmail-reject
+++ b/fail2ban/tests/files/logs/sendmail-reject
@@ -40,6 +40,8 @@ Feb 19 18:01:50 batman sm-mta[78152]: ruleset=check_relay, arg1=[196.213.73.146]
 
 # failJSON: { "time": "2005-02-27T10:53:06", "match": true , "host": "209.15.212.253" }
 Feb 27 10:53:06 batman sm-mta[44307]: s1R9r60D044307: rejecting commands from  [209.15.212.253] due to pre-greeting traffic after 0 seconds
+# failJSON: { "time": "2005-02-27T10:53:07", "match": true , "host": "1.2.3.4" }
+Feb 27 10:53:07 strange sm-mta[18001]: u9A0GtpL018001: rejecting commands from example.com [1.2.3.4] due to pre-greeting traffic after 6 seconds
 
 # failJSON: { "time": "2005-02-27T15:44:18", "match": true , "host": "41.204.78.137" }
 Feb 27 15:44:18 batman sm-mta[87838]: s1REiHdq087838: ruleset=check_rcpt, arg1=<gert-jan@t-online.ch>, relay=[41.204.78.137], reject=550 5.7.1 <gert-jan@t-online.ch>... Relaying denied. IP name lookup failed [41.204.78.137]