I have run my own mail server about as long, run an RBL, and a transactional mail service too. This is a hard line approach and blacklisting a /24 on a second offense that never expires just doesn't work long term but at least you are not completely blocking it and accepting it but as spam.
Lets be real there is spam coming from gmail and hotmail/outlook as well and places like abuseix specifically state they don't block these ranges. So the large providers get excused for clean up because they are too big. Sure blocking colo crossing probably won't get any one to complain, but Digital Ocean is probably going to get some collateral damage. For your own mail server fine, don't accept it, send to spam - but there is a reason real RBL lists are very careful to skip the big providers or make sure they expire. Spamcop always had the best method - expire when the spam stops. Does it keep getting listing? Keep it longer. Rspamd also has a good method where an RBL increases the score. The hard line approach gives gmail and microsoft a large share of the email market and hurts smaller providers when they are not held to the same standards as everyone else. If gmail emails start bouncing when they have a heavy spam hit, then maybe gmail users will change isps and help gmail clean up. These are two trillion dollar companies that also have spam problems.
As far as UCEprotect. Their level1 is actually reasonable, especially for spam traps. The timestamps easily allow for you to find exactly what the spam is from with the smtp response and time frame. Their scanning methods are less so. Dos prevention measures can get you listed there and are not valid. The level2/3 lists are utter shit.
I think the issue is that, short of customers running their own BGP routers and hosting their own subnet, anything smaller than a /24 assigned by the ISP is completely transparent to BGP databases and thus spam filters / IP reputation databases.
Lets be real there is spam coming from gmail and hotmail/outlook as well and places like abuseix specifically state they don't block these ranges. So the large providers get excused for clean up because they are too big. Sure blocking colo crossing probably won't get any one to complain, but Digital Ocean is probably going to get some collateral damage. For your own mail server fine, don't accept it, send to spam - but there is a reason real RBL lists are very careful to skip the big providers or make sure they expire. Spamcop always had the best method - expire when the spam stops. Does it keep getting listing? Keep it longer. Rspamd also has a good method where an RBL increases the score. The hard line approach gives gmail and microsoft a large share of the email market and hurts smaller providers when they are not held to the same standards as everyone else. If gmail emails start bouncing when they have a heavy spam hit, then maybe gmail users will change isps and help gmail clean up. These are two trillion dollar companies that also have spam problems.
As far as UCEprotect. Their level1 is actually reasonable, especially for spam traps. The timestamps easily allow for you to find exactly what the spam is from with the smtp response and time frame. Their scanning methods are less so. Dos prevention measures can get you listed there and are not valid. The level2/3 lists are utter shit.