diff --git a/apps/portal/server/api/apple-mailconfig.get.ts b/apps/portal/server/api/apple-mailconfig.get.ts
index e5fa51d..0eeadc3 100644
--- a/apps/portal/server/api/apple-mailconfig.get.ts
+++ b/apps/portal/server/api/apple-mailconfig.get.ts
@@ -36,7 +36,8 @@ export default defineEventHandler(async (event) => {
   }
 
   const mailHost = new URL(useRuntimeConfig().public.mailUrl as string).host
-  const localPart = email.split('@')[0]
+  // The regex above guarantees an @, but noUncheckedIndexedAccess doesn't know.
+  const localPart = email.split('@')[0] ?? email
   const accountUuid = randomUUID()
   const profileUuid = randomUUID()
   const e = xmlEscape(email)