Static IP address
|Anti-spam technique: Static IP address|
|Date of first use:||mid 1990s|
|Popularity:||High, built into many MTAs|
|Difficulty of implementation:||easy|
|Where implemented:||MTA, with difficulty in MUAs|
Manually maintained IP blocks work well against fixed spam sources, of which there are plenty. Their main shortcoming is the work involved in maintaining the lists. Manual lists are popular and often poorly maintained, to the extent that even after a spammer is removed from an IP range, the range remains in many manual blacklists, limiting its utility to anyone else.