diff --git a/CHANGELOG.md b/CHANGELOG.md
index 003ec1b8..1574255b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 # Changelog
 
+### 6.0.0-beta.3 / TBD
+* Fixed issue when sending message without attachments
+
 ### 6.0.0-beta.2 / 2023-11-21
 * Added additional error classes
 * Added support for free/busy endpoint
diff --git a/lib/nylas/utils/file_utils.rb b/lib/nylas/utils/file_utils.rb
index 75b15d66..01514a14 100644
--- a/lib/nylas/utils/file_utils.rb
+++ b/lib/nylas/utils/file_utils.rb
@@ -11,9 +11,14 @@ module FileUtils
     # @!visibility private
     def self.build_form_request(request_body)
       attachments = request_body.delete(:attachments) || request_body.delete("attachments") || []
-      message_payload = request_body.to_json
+
+      # RestClient will not send a multipart request if there are no attachments
+      # so we need to return the message payload to be used as a json payload
+      return [request_body, []] if attachments.empty?
 
       # Prepare the data to return
+      message_payload = request_body.to_json
+
       form_data = {}
       opened_files = []