Check result of IP
45.145.222.20
This is the rDNS found:
This IP was blocked by bad reputation in 100% of negative points.
In order for the IP to be removed from this list, the source MTA has to reduce the deliveries to customers who have complained, which have generated a SPFBL rejection prefix at the SMTP layer.
The reputation interval is seven days, so you should wait for this interval after all abuse has stopped.