diff --git a/src/mail.js b/src/mail.js
index 22a66171c..3b2ee3244 100644
--- a/src/mail.js
+++ b/src/mail.js
@@ -1267,13 +1267,15 @@ async function setAliases(name, domain, aliases) {
     assert(Array.isArray(aliases));
 
     for (let i = 0; i < aliases.length; i++) {
-        let name = aliases[i].name.toLowerCase();
-        let domain = aliases[i].domain.toLowerCase();
+        const name = aliases[i].name.toLowerCase();
+        const domain = aliases[i].domain.toLowerCase();
 
-        let error = validateName(name);
+        const error = validateName(name);
         if (error) throw error;
 
-        if (!validator.isEmail(`${name}@${domain}`)) throw new BoxError(BoxError.BAD_FIELD, `Invalid email: ${name}@${domain}`);
+        const mailDomain = await getDomain(domain);
+        if (!mailDomain) throw new BoxError(BoxError.NOT_FOUND, `mail domain ${domain} not found`);
+
         aliases[i] = { name, domain };
     }