CONCORD Spam Prevention Act Charge. The purpose of the CSPA charge is to prevent players from sending you unsolicited spam in the form of eve mails, chat, or fleet invitations. Players in your address book are exempt from these charges.
By default, every player account has a CSPA charge set to 2950 ISK, which may be configured to 1,000,000 ISK. This ISK is not sent to your wallet, but is rather sent to CONCORD, an NPC-controlled organization. Before any charge is made, a window pops-up asking to confirm whether they want to accept the charge. When a fleet commander is trying to get fifty or more fleet invitations sent, these pop-up windows get in the way and piss them off.
Since it's mostly ineffective against actual spammers, it's best solution is to turn the feature off as soon as possible.
 Disabling CSPA Charges
The easiest way to disable charges is to just switch them off for everybody. To do that:
- Open EVE mail by clicking on the letter icon.
- Click on the small white triangle next to the Eve Mail window title
- Select settings
- Enter 0 in the CSPA Charge field
- Click "Apply". The Window will close and the CSPA charge will be disabled.