refactor: update dependencies

src/smtp.ts

@@ -354,7 +354,7 @@ export class SMTP extends VerifiableTransport {
       /* tslint:disable-next-line:no-console */
       console.warn(
         'SMTP verification error was ignored, because tranport failures are allowed: ',
-        err.message,
+        (err as Error).message,
       );
     }