diff --git a/CHANGELOG b/CHANGELOG
index 99ec4d3b3..a887f1983 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -47,6 +47,7 @@ CHANGELOG Roundcube Webmail
 - Elastic: Fix redundant scrollbar in plain text editor on mail reply (#7500)
 - Elastic: Fix deleted and replied+forwarded icons on messages list (#7503)
 - Managesieve: Allow angle brackets in out-of-office message body (#7518)
+- Fix bug in conversion of email addresses to mailto links in plain text messages (#7526)
 - Fix format=flowed formatting on plain text part derived from the HTML content (#7504)
 - Fix incorrect rewriting of internal links in HTML content (#7512)
 - Fix handling links without defined protocol (#7454)
diff --git a/program/lib/Roundcube/rcube_string_replacer.php b/program/lib/Roundcube/rcube_string_replacer.php
index cad259617..34a8a94ac 100644
--- a/program/lib/Roundcube/rcube_string_replacer.php
+++ b/program/lib/Roundcube/rcube_string_replacer.php
@@ -59,10 +59,10 @@ class rcube_string_replacer
         $this->linkref_pattern = '/\[([^\]#]+)\]/';
         $this->link_pattern    = "/$link_prefix($utf_domain([$url1]*[$url2]+)*)/";
         $this->mailto_pattern  = "/("
-            ."[-\w!\#\$%&\'*+~\/^`|{}=]+(?:\.[-\w!\#\$%&\'*+~\/^`|{}=]+)*"  // local-part
-            ."@$utf_domain"                                                 // domain-part
-            ."(\?[$url1$url2]+)?"                                           // e.g. ?subject=test...
-            .")/";
+            . "[-\w!\#\$%&*+~\/^`|{}=]+(?:\.[-\w!\#\$%&*+~\/^`|{}=]+)*"  // local-part
+            . "@$utf_domain"                                             // domain-part
+            . "(\?[$url1$url2]+)?"                                       // e.g. ?subject=test...
+            . ")/";
     }
 
     /**
diff --git a/tests/Framework/StringReplacer.php b/tests/Framework/StringReplacer.php
index 6adaee4ce..07649bd01 100644
--- a/tests/Framework/StringReplacer.php
+++ b/tests/Framework/StringReplacer.php
@@ -39,8 +39,10 @@ class Framework_StringReplacer extends PHPUnit\Framework\TestCase
             array('https://github.com/a/b/compare/3a0f82...1f4b2a after', '<a href="https://github.com/a/b/compare/3a0f82...1f4b2a">https://github.com/a/b/compare/3a0f82...1f4b2a</a> after'),
             array('http://<test>', 'http://<test>'),
             array('http://', 'http://'),
-            array('test@www.test', '<a href="mailto:test@www.test">test@www.test</a>'),
-            array('1@1.com www.domain.tld', '<a href="mailto:1@1.com">1@1.com</a> <a href="http://www.domain.tld">www.domain.tld</a>'),
+            array('test test@www.test test', 'test <a href="mailto:test@www.test">test@www.test</a> test'),
+            array("test 'test@www.test' test", "test '<a href=\"mailto:test@www.test\">test@www.test</a>' test"),
+            array('test "test@www.test" test', 'test "<a href="mailto:test@www.test">test@www.test</a>" test'),
+            array('a 1@1.com www.domain.tld', 'a <a href="mailto:1@1.com">1@1.com</a> <a href="http://www.domain.tld">www.domain.tld</a>'),
             array(' www.domain.tld ', ' <a href="http://www.domain.tld">www.domain.tld</a> '),
             array(' www.domain.tld/#!download|856p1|2 ', ' <a href="http://www.domain.tld/#!download|856p1|2">www.domain.tld/#!download|856p1|2</a> '),
             // #1489898: allow some unicode characters