Black listing methods for spamming emails

Question

If someone gets access to your server and setup an e-mail spam service. Will the online black listing services than block this individual ip address that this server uses, or will they black list your block?

Answer 1

Either is possible, however it is most likely only your IP address would be blocked. As a general rule, the blacklisting providers don't know how big a block is, so won't know what the size of your range is.

A couple of notes - if you are in a dynamic pool, or pool associated with cheap/home connections - a lot of these are mapped out and per-emptively blocked by range by some providers. Similarly, if a lot of the IP's in the range send spam, then the spam blockers might look to aggregate these into a single bigger block.

Note that there are 2 common types of IP address block. Things like senderbase will be a temporary block and will restore your access days-weeks after the spamming has stopped. there are also RBLs which you should check and may need to request manual de-listing from.