Take a look at
Force Read Receipt & Auto-Accept Read Receipt | Zimbra :: Gallery Zimlet. This Zimlet first checks if "zimbraPrefMailSendReadReceipts" property is set to always, if not it sets "zimbraPrefMailSendReadReceipts" to "always".
<code>
/**
* Sets Send read-receipt to "Always"
*/
ForceReadReceiptZimlet.prototype.setSendReceiptToA lways =
function() {
if(appCtxt.getActiveAccount().settings.get("MAIL_S END_READ_RECEIPTS") == "always") {
return;
}
if (appCtxt.get(ZmSetting.MAIL_READ_RECEIPT_ENABLED)) {
var soapDoc = AjxSoapDoc.create("ModifyPrefsRequest", "urn:zimbraAccount");
var node = soapDoc.set("pref", "always");
node.setAttribute("name", "zimbraPrefMailSendReadReceipts");
var respCallback = new AjxCallback(this, this._handlePrefChangeResponse);
appCtxt.getAppController().sendRequest({soapDoc:so apDoc, asyncMode:true, callback:respCallback});
}
};
</code>