Microsoft Graph API)Is any option create message from a MIME, NOT as Draft?

Question

I am Using Microsoft Graph REST API 1.0, trying to create a new message (not draft) from a MIME but I came into some issues.

I managed to create a message using a base64 encoded MIME but it gets flagged as a draft (isDraft=true) (https://learn.microsoft.com/en-us/graph/api/user-post-messages?view=graph-rest-1.0&tabs=http)

According to multiple sources isDraft flag can only be set at message creation so I take the previously created message, change isDraft flag to false using a SingleValueLegacyExtendedProperty and I POST it to the inbox but the original MIME headers get modified (a lot of the original removed, some new created) and I need to keep them like the original.

Why MIME original headers are modified after change isDraft and respost the same message? Is there a way to avoid this behavior?

Also if there is another aproach to archive what I want, please let me know.

Thanks!

Some of my code below

// Create a new message (Original MIME)  
newMessage = (Message) graphServiceClient  
        .customRequest(String.format("/users/%s/messages/", USER_EMAIL), Message.class)  
        .buildRequest(new HeaderOption("Content-Type", "text/plain"))  
        .post(Base64.encodeBase64(IOUtils.toByteArray(  
            Objects.requireNonNull(  
                this.getClass().getClassLoader().getResourceAsStream(  
                    MIME_MAIL_WITH_ATTACHMENTS)))));  
  
//flag newMessage as draft (despite that newMessage has the original headers, after this update they become different from the original)                     
newMessage.singleValueExtendedProperties = setDraftFalse();  
  
  private SingleValueLegacyExtendedPropertyCollectionPage setDraftFalse() {  
    final SingleValueLegacyExtendedProperty prop = new SingleValueLegacyExtendedProperty();  
    prop.id = "Integer 0x0E07";  
    prop.value = "4";  
  
    final SingleValueLegacyExtendedPropertyCollectionResponse response = new SingleValueLegacyExtendedPropertyCollectionResponse();  
    response.value = new ArrayList<SingleValueLegacyExtendedProperty>();  
    response.value.add(prop);  
    return new SingleValueLegacyExtendedPropertyCollectionPage(  
        response, null);  
  }  
  
// Post the message updated   
graphServiceClient.me().messages().buildRequest().post(newMessage);