diff --git a/src/core/operations/RegularExpression.mjs b/src/core/operations/RegularExpression.mjs
index 9ea17e83..e0ecd7cc 100644
--- a/src/core/operations/RegularExpression.mjs
+++ b/src/core/operations/RegularExpression.mjs
@@ -45,7 +45,7 @@ class RegularExpression extends Operation {
                     },
                     {
                         name: "Email address",
-                        value: "(?:[\\u00A0-\\uD7FF\\uE000-\\uFFFFa-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\\.[\\u00A0-\\uD7FF\\uE000-\\uFFFFa-z0-9!#$%&'*+/=?^_`{|}~-]+)*|\"(?:[\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x21\\x23-\\x5b\\x5d-\\x7f]|\\[\\x01-\\x09\\x0b\\x0c\\x0e-\\x7f])*\")@(?:(?:[\\u00A0-\\uD7FF\\uE000-\\uFFFFa-z0-9](?:[\\u00A0-\\uD7FF\\uE000-\\uFFFF-a-z0-9-]*[\\u00A0-\\uD7FF\\uE000-\\uFFFFa-z0-9])?\\.)+[\\u00A0-\\uD7FF\\uE000-\\uFFFFa-z0-9](?:[\\u00A0-\\uD7FF\\uE000-\\uFFFFa-z0-9-]*[\\u00A0-\\uD7FF\\uE000-\\uFFFFa-z0-9])?|\\[(?:(?:(2(5[0-5]|[0-4][0-9])|1[0-9][0-9]|[1-9]?[0-9]))\\.){3}\\])"
+                        value: "(?:[\u00A0-\uD7FF\uE000-\uFFFFa-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[\u00A0-\uD7FF\uE000-\uFFFFa-z0-9!#$%&'*+/=?^_`{|}~-]+)*|"(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])*")@(?:(?:[\u00A0-\uD7FF\uE000-\uFFFFa-z0-9](?:[\u00A0-\uD7FF\uE000-\uFFFFa-z0-9-]*[\u00A0-\uD7FF\uE000-\uFFFFa-z0-9])?\.)+[\u00A0-\uD7FF\uE000-\uFFFFa-z0-9](?:[\u00A0-\uD7FF\uE000-\uFFFFa-z0-9-]*[\u00A0-\uD7FF\uE000-\uFFFFa-z0-9])?|\[(?:(?:(2(5[0-5]|[0-4][0-9])|1[0-9][0-9]|[1-9]?[0-9]))\.){3}(?:(2(5[0-5]|[0-4][0-9])|1[0-9][0-9]|[1-9]?[0-9]))\])"
                     },
                     {
                         name: "URL",
diff --git a/tests/operations/index.mjs b/tests/operations/index.mjs
index f147e9e7..7c42cd11 100644
--- a/tests/operations/index.mjs
+++ b/tests/operations/index.mjs
@@ -137,6 +137,7 @@ import "./tests/Rabbit.mjs";
 import "./tests/RAKE.mjs";
 import "./tests/Regex.mjs";
 import "./tests/Register.mjs";
+import "./tests/RegularExpression.mjs";
 import "./tests/RisonEncodeDecode.mjs";
 import "./tests/Rotate.mjs";
 import "./tests/RSA.mjs";
diff --git a/tests/operations/tests/ExtractEmailAddresses.mjs b/tests/operations/tests/ExtractEmailAddresses.mjs
index 658484cf..97ff7e3e 100644
--- a/tests/operations/tests/ExtractEmailAddresses.mjs
+++ b/tests/operations/tests/ExtractEmailAddresses.mjs
@@ -11,44 +11,70 @@ TestRegister.addTests([
     {
         name: "Extract email address",
         input: "email@example.com\nfirstname.lastname@example.com\nemail@subdomain.example.com\nfirstname+lastname@example.com\n1234567890@example.com\nemail@example-one.com\n_______@example.com email@example.name\nemail@example.museum email@example.co.jp firstname-lastname@example.com",
-        expectedOutput: "email@example.com\nfirstname.lastname@example.com\nemail@subdomain.example.com\nfirstname+lastname@example.com\n1234567890@example.com\nemail@example-one.com\n_______@example.com\nemail@example.name\nemail@example.museum\nemail@example.co.jp\nfirstname-lastname@example.com",
+        expectedOutput:
+            "email@example.com\nfirstname.lastname@example.com\nemail@subdomain.example.com\nfirstname+lastname@example.com\n1234567890@example.com\nemail@example-one.com\n_______@example.com\nemail@example.name\nemail@example.museum\nemail@example.co.jp\nfirstname-lastname@example.com",
         recipeConfig: [
             {
-                "op": "Extract email addresses",
-                "args": [false]
+                op: "Extract email addresses",
+                args: [false],
             },
         ],
     },
     {
         name: "Extract email address - Display total",
         input: "email@example.com\nfirstname.lastname@example.com\nemail@subdomain.example.com\nfirstname+lastname@example.com\n1234567890@example.com\nemail@example-one.com\n_______@example.com email@example.name\nemail@example.museum email@example.co.jp firstname-lastname@example.com",
-        expectedOutput: "Total found: 11\n\nemail@example.com\nfirstname.lastname@example.com\nemail@subdomain.example.com\nfirstname+lastname@example.com\n1234567890@example.com\nemail@example-one.com\n_______@example.com\nemail@example.name\nemail@example.museum\nemail@example.co.jp\nfirstname-lastname@example.com",
+        expectedOutput:
+            "Total found: 11\n\nemail@example.com\nfirstname.lastname@example.com\nemail@subdomain.example.com\nfirstname+lastname@example.com\n1234567890@example.com\nemail@example-one.com\n_______@example.com\nemail@example.name\nemail@example.museum\nemail@example.co.jp\nfirstname-lastname@example.com",
         recipeConfig: [
             {
-                "op": "Extract email addresses",
-                "args": [true]
+                op: "Extract email addresses",
+                args: [true],
             },
         ],
     },
     {
         name: "Extract email address (Internationalized)",
         input: "\u4f0a\u662d\u5091@\u90f5\u4ef6.\u5546\u52d9 \u093e\u092e@\u092e\u094b\u0939\u0928.\u0908\u0928\u094d\u092b\u094b\n\u044e\u0437\u0435\u0440@\u0435\u043a\u0437\u0430\u043c\u043f\u043b.\u043a\u043e\u043c \u03b8\u03c3\u03b5\u03c1@\u03b5\u03c7\u03b1\u03bc\u03c0\u03bb\u03b5.\u03c8\u03bf\u03bc Jos\u1ec5Silv\u1ec5@googl\u1ec5.com\nJos\u1ec5Silv\u1ec5@google.com and Jos\u1ec5Silva@google.com\nFoO@BaR.CoM, john@192.168.10.100\ng\xf3mez@junk.br and Abc.123@example.com.\nuser+mailbox/department=shipping@example.com\n\u7528\u6237@\u4f8b\u5b50.\u5e7f\u544a\n\u0909\u092a\u092f\u094b\u0917\u0915\u0930\u094d\u0924\u093e@\u0909\u0926\u093e\u0939\u0930\u0923.\u0915\u0949\u092e\n\u044e\u0437\u0435\u0440@\u0435\u043a\u0437\u0430\u043c\u043f\u043b.\u043a\u043e\u043c\n\u03b8\u03c3\u03b5\u03c1@\u03b5\u03c7\u03b1\u03bc\u03c0\u03bb\u03b5.\u03c8\u03bf\u03bc\nD\xf6rte@S\xf6rensen.example.com\n\u0430\u0434\u0436\u0430\u0439@\u044d\u043a\u0437\u0430\u043c\u043f\u043b.\u0440\u0443\u0441\ntest@xn--bcher-kva.com",
-        expectedOutput: "\u4f0a\u662d\u5091@\u90f5\u4ef6.\u5546\u52d9\n\u093e\u092e@\u092e\u094b\u0939\u0928.\u0908\u0928\u094d\u092b\u094b\n\u044e\u0437\u0435\u0440@\u0435\u043a\u0437\u0430\u043c\u043f\u043b.\u043a\u043e\u043c\n\u03b8\u03c3\u03b5\u03c1@\u03b5\u03c7\u03b1\u03bc\u03c0\u03bb\u03b5.\u03c8\u03bf\u03bc\nJos\u1ec5Silv\u1ec5@googl\u1ec5.com\nJos\u1ec5Silv\u1ec5@google.com\nJos\u1ec5Silva@google.com\nFoO@BaR.CoM\njohn@192.168.10.100\ng\xf3mez@junk.br\nAbc.123@example.com\nuser+mailbox/department=shipping@example.com\n\u7528\u6237@\u4f8b\u5b50.\u5e7f\u544a\n\u0909\u092a\u092f\u094b\u0917\u0915\u0930\u094d\u0924\u093e@\u0909\u0926\u093e\u0939\u0930\u0923.\u0915\u0949\u092e\n\u044e\u0437\u0435\u0440@\u0435\u043a\u0437\u0430\u043c\u043f\u043b.\u043a\u043e\u043c\n\u03b8\u03c3\u03b5\u03c1@\u03b5\u03c7\u03b1\u03bc\u03c0\u03bb\u03b5.\u03c8\u03bf\u03bc\nD\xf6rte@S\xf6rensen.example.com\n\u0430\u0434\u0436\u0430\u0439@\u044d\u043a\u0437\u0430\u043c\u043f\u043b.\u0440\u0443\u0441\ntest@xn--bcher-kva.com",
+        expectedOutput:
+            "\u4f0a\u662d\u5091@\u90f5\u4ef6.\u5546\u52d9\n\u093e\u092e@\u092e\u094b\u0939\u0928.\u0908\u0928\u094d\u092b\u094b\n\u044e\u0437\u0435\u0440@\u0435\u043a\u0437\u0430\u043c\u043f\u043b.\u043a\u043e\u043c\n\u03b8\u03c3\u03b5\u03c1@\u03b5\u03c7\u03b1\u03bc\u03c0\u03bb\u03b5.\u03c8\u03bf\u03bc\nJos\u1ec5Silv\u1ec5@googl\u1ec5.com\nJos\u1ec5Silv\u1ec5@google.com\nJos\u1ec5Silva@google.com\nFoO@BaR.CoM\njohn@192.168.10.100\ng\xf3mez@junk.br\nAbc.123@example.com\nuser+mailbox/department=shipping@example.com\n\u7528\u6237@\u4f8b\u5b50.\u5e7f\u544a\n\u0909\u092a\u092f\u094b\u0917\u0915\u0930\u094d\u0924\u093e@\u0909\u0926\u093e\u0939\u0930\u0923.\u0915\u0949\u092e\n\u044e\u0437\u0435\u0440@\u0435\u043a\u0437\u0430\u043c\u043f\u043b.\u043a\u043e\u043c\n\u03b8\u03c3\u03b5\u03c1@\u03b5\u03c7\u03b1\u03bc\u03c0\u03bb\u03b5.\u03c8\u03bf\u03bc\nD\xf6rte@S\xf6rensen.example.com\n\u0430\u0434\u0436\u0430\u0439@\u044d\u043a\u0437\u0430\u043c\u043f\u043b.\u0440\u0443\u0441\ntest@xn--bcher-kva.com",
         recipeConfig: [
             {
-                "op": "Extract email addresses",
-                "args": [false]
+                op: "Extract email addresses",
+                args: [false],
             },
         ],
     },
     {
         name: "Extract email address - Display total (Internationalized)",
         input: "\u4f0a\u662d\u5091@\u90f5\u4ef6.\u5546\u52d9 \u093e\u092e@\u092e\u094b\u0939\u0928.\u0908\u0928\u094d\u092b\u094b\n\u044e\u0437\u0435\u0440@\u0435\u043a\u0437\u0430\u043c\u043f\u043b.\u043a\u043e\u043c \u03b8\u03c3\u03b5\u03c1@\u03b5\u03c7\u03b1\u03bc\u03c0\u03bb\u03b5.\u03c8\u03bf\u03bc Jos\u1ec5Silv\u1ec5@googl\u1ec5.com\nJos\u1ec5Silv\u1ec5@google.com and Jos\u1ec5Silva@google.com\nFoO@BaR.CoM, john@192.168.10.100\ng\xf3mez@junk.br and Abc.123@example.com.\nuser+mailbox/department=shipping@example.com\n\u7528\u6237@\u4f8b\u5b50.\u5e7f\u544a\n\u0909\u092a\u092f\u094b\u0917\u0915\u0930\u094d\u0924\u093e@\u0909\u0926\u093e\u0939\u0930\u0923.\u0915\u0949\u092e\n\u044e\u0437\u0435\u0440@\u0435\u043a\u0437\u0430\u043c\u043f\u043b.\u043a\u043e\u043c\n\u03b8\u03c3\u03b5\u03c1@\u03b5\u03c7\u03b1\u03bc\u03c0\u03bb\u03b5.\u03c8\u03bf\u03bc\nD\xf6rte@S\xf6rensen.example.com\n\u0430\u0434\u0436\u0430\u0439@\u044d\u043a\u0437\u0430\u043c\u043f\u043b.\u0440\u0443\u0441\ntest@xn--bcher-kva.com",
-        expectedOutput: "Total found: 19\n\n\u4f0a\u662d\u5091@\u90f5\u4ef6.\u5546\u52d9\n\u093e\u092e@\u092e\u094b\u0939\u0928.\u0908\u0928\u094d\u092b\u094b\n\u044e\u0437\u0435\u0440@\u0435\u043a\u0437\u0430\u043c\u043f\u043b.\u043a\u043e\u043c\n\u03b8\u03c3\u03b5\u03c1@\u03b5\u03c7\u03b1\u03bc\u03c0\u03bb\u03b5.\u03c8\u03bf\u03bc\nJos\u1ec5Silv\u1ec5@googl\u1ec5.com\nJos\u1ec5Silv\u1ec5@google.com\nJos\u1ec5Silva@google.com\nFoO@BaR.CoM\njohn@192.168.10.100\ng\xf3mez@junk.br\nAbc.123@example.com\nuser+mailbox/department=shipping@example.com\n\u7528\u6237@\u4f8b\u5b50.\u5e7f\u544a\n\u0909\u092a\u092f\u094b\u0917\u0915\u0930\u094d\u0924\u093e@\u0909\u0926\u093e\u0939\u0930\u0923.\u0915\u0949\u092e\n\u044e\u0437\u0435\u0440@\u0435\u043a\u0437\u0430\u043c\u043f\u043b.\u043a\u043e\u043c\n\u03b8\u03c3\u03b5\u03c1@\u03b5\u03c7\u03b1\u03bc\u03c0\u03bb\u03b5.\u03c8\u03bf\u03bc\nD\xf6rte@S\xf6rensen.example.com\n\u0430\u0434\u0436\u0430\u0439@\u044d\u043a\u0437\u0430\u043c\u043f\u043b.\u0440\u0443\u0441\ntest@xn--bcher-kva.com",
+        expectedOutput:
+            "Total found: 19\n\n\u4f0a\u662d\u5091@\u90f5\u4ef6.\u5546\u52d9\n\u093e\u092e@\u092e\u094b\u0939\u0928.\u0908\u0928\u094d\u092b\u094b\n\u044e\u0437\u0435\u0440@\u0435\u043a\u0437\u0430\u043c\u043f\u043b.\u043a\u043e\u043c\n\u03b8\u03c3\u03b5\u03c1@\u03b5\u03c7\u03b1\u03bc\u03c0\u03bb\u03b5.\u03c8\u03bf\u03bc\nJos\u1ec5Silv\u1ec5@googl\u1ec5.com\nJos\u1ec5Silv\u1ec5@google.com\nJos\u1ec5Silva@google.com\nFoO@BaR.CoM\njohn@192.168.10.100\ng\xf3mez@junk.br\nAbc.123@example.com\nuser+mailbox/department=shipping@example.com\n\u7528\u6237@\u4f8b\u5b50.\u5e7f\u544a\n\u0909\u092a\u092f\u094b\u0917\u0915\u0930\u094d\u0924\u093e@\u0909\u0926\u093e\u0939\u0930\u0923.\u0915\u0949\u092e\n\u044e\u0437\u0435\u0440@\u0435\u043a\u0437\u0430\u043c\u043f\u043b.\u043a\u043e\u043c\n\u03b8\u03c3\u03b5\u03c1@\u03b5\u03c7\u03b1\u03bc\u03c0\u03bb\u03b5.\u03c8\u03bf\u03bc\nD\xf6rte@S\xf6rensen.example.com\n\u0430\u0434\u0436\u0430\u0439@\u044d\u043a\u0437\u0430\u043c\u043f\u043b.\u0440\u0443\u0441\ntest@xn--bcher-kva.com",
         recipeConfig: [
             {
-                "op": "Extract email addresses",
-                "args": [true]
+                op: "Extract email addresses",
+                args: [true],
+            },
+        ],
+    },
+    {
+        name: "Extract email address - IP address",
+        input: "yaunwfkb\nexample@[127.0.0.1]\n091nvka",
+        expectedOutput: "example@[127.0.0.1]",
+        recipeConfig: [
+            {
+                op: "Extract email addresses",
+                args: [false],
+            },
+        ],
+    },
+    {
+        name: "Extract email address - invalid IP address",
+        input: "yaunwfkb\nfalse_positive@[1.2.3.]\n091nvka",
+        expectedOutput: "",
+        recipeConfig: [
+            {
+                op: "Extract email addresses",
+                args: [false],
             },
         ],
     },
diff --git a/tests/operations/tests/RegularExpression.mjs b/tests/operations/tests/RegularExpression.mjs
new file mode 100644
index 00000000..6c560ecf
--- /dev/null
+++ b/tests/operations/tests/RegularExpression.mjs
@@ -0,0 +1,53 @@
+/**
+ * Regular Expression tests.
+ *
+ * @author C85297 [95289555+C85297@users.noreply.github.com]
+ * @copyright Crown Copyright 2017
+ * @license Apache-2.0
+ */
+import TestRegister from "../../lib/TestRegister.mjs";
+
+TestRegister.addTests([
+    {
+        name: "Regular Expression - built in email regex - IP address",
+        input: "yaunwfkb\nexample@[127.0.0.1]\n091nvka",
+        expectedOutput: "example@[127.0.0.1]",
+        recipeConfig: [
+            {
+                op: "Regular expression",
+                args: [
+                    "Email address",
+                    null,
+                    true,
+                    true,
+                    false,
+                    false,
+                    false,
+                    false,
+                    "List matches",
+                ],
+            },
+        ],
+    },
+    {
+        name: "Regular Expression - built in email regex - invalid IP address",
+        input: "yaunwfkb\false_positive@[1.2.3.]\n091nvka",
+        expectedOutput: "",
+        recipeConfig: [
+            {
+                op: "Regular expression",
+                args: [
+                    "Email address",
+                    null,
+                    true,
+                    true,
+                    false,
+                    false,
+                    false,
+                    false,
+                    "List matches",
+                ],
+            },
+        ],
+    },
+]);