In rare cases, when integrating with third-party networks and using S2S postback to communicate information to your Post Affiliate Pro (Network), you may receive a 200 OK response, but the request will not appear in either the Tools → Event Logs or Tools → Sale Requests Log.
The most likely cause is that the network you are connecting with includes the string "robot" in the User-Agent header of its requests.
To prevent search engine crawlers and bots from triggering tracking scripts (such as click.php, track.php, or sale.php), we block any communication that contains any of the following strings in the User-Agent header:
'googlebot', 'robot', 'slurp', 'yahooseeker', 'teoma', 'crawl', 'spider', 'msnbot', 'bingbot', 'adsbot', 'twitterbot', 'niki-bot', 'hrbot', 'yandex.com/bots'
For example, if your network identifies itself as 'NetworkRobot', this communication will be blocked. In such cases, it is necessary to whitelist the User-Agent before you can successfully accept S2S postbacks from that network.