cURL Error 28 - IP blocked?

Hi there,

we suddenly cannot install plugins from WPMUDEV via the Dev-Plugin on this site anymore. Due to the fact that the site in question had a malware problem (which we tried to fix by resetting the site but then ending up completely removing and rebuilding it) we reckon that maybe we are on a blacklist of yours? Can you please provide feedback and/or advice on how to proceed? Will grant Admin access in a minute.

Best regards and thank you in advance,
Stefan