diff --git a/src/lib/util.ts b/src/lib/util.ts
new file mode 100644
index 0000000..b6600fa
--- /dev/null
+++ b/src/lib/util.ts
@@ -0,0 +1,13 @@
+
+function check_email_format(email: string) {
+	const trimmed = email.trim()
+
+	if (trimmed.length > 254) return false
+
+	const emailRegex = /^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9-]+(?:.[a-zA-Z0-9-]+)*$/;
+	return emailRegex.test(trimmed)
+}
+
+export default {
+	check_email_format,
+}