diff --git a/src/caller/message/event.rs b/src/caller/message/event.rs
index ea25f4f..e15d31a 100644
--- a/src/caller/message/event.rs
+++ b/src/caller/message/event.rs
@@ -7,7 +7,8 @@ pub mod request {
         pub scheduled_message_event_id: uuid::Uuid,
         pub response: String,
         pub user_id: uuid::Uuid,
-        pub sent: time::OffsetDateTime,
+        #[serde(with = "time::serde::rfc3339::option")]
+        pub sent: Option<time::OffsetDateTime>,
         pub status: String,
         pub contact_id: uuid::Uuid,
         pub message_id: uuid::Uuid,
@@ -15,7 +16,7 @@ pub mod request {
 
     impl RecordMessageEventRequest {
         pub fn is_valid(&self) -> bool {
-            false
+            !self.scheduled_message_event_id.is_nil() || !self.response.is_empty() || !self.user_id.is_nil() || self.sent.is_some() || !self.status.is_empty() || !self.contact_id.is_nil() || !self.message_id.is_nil()
         }
     }
 }
@@ -62,7 +63,7 @@ pub mod endpoint {
             let mut mer = textsender_models::message::event::MessageEventResponse {
                 scheduled_message_event_id: payload.scheduled_message_event_id,
                 user_id: payload.user_id,
-                sent: Some(payload.sent),
+                sent: payload.sent,
                 status: payload.status,
                 contact_id: payload.contact_id,
                 message_id: payload.message_id,