diff --git a/src/utils/sanitizer.utils.ts b/src/utils/sanitizer.utils.ts
index 4115525..9619536 100644
--- a/src/utils/sanitizer.utils.ts
+++ b/src/utils/sanitizer.utils.ts
@@ -24,7 +24,7 @@ function cleanNrcc(input: string) {
 function getDomainFromEmail(mail: string) {
   // Needs testing
   let split = mail.split("@");
-  return split[1];
+  return split[1].toLowerCase();
 }
 
 module.exports = {
diff --git a/test/utils/sanitizer.utils.test.ts b/test/utils/sanitizer.utils.test.ts
index 8bd7b59..19ff938 100644
--- a/test/utils/sanitizer.utils.test.ts
+++ b/test/utils/sanitizer.utils.test.ts
@@ -9,6 +9,7 @@ describe("Sanitize Email", () => {
     "I%Have{Special}%Characters@example.com",
     "Basic.address@example.com",
     `"very.(),:;<>[]\".VERY.\"very\ \"very\".unusual"@example.com`,
+    "THIS_EMAIL_CONTAINS_CAPITALISED_DOMAIN@EXAMPLE.COM"
   ];
   const expectedOutput = "example.com";
   for (const addr of inputs) {