MailCaptcha
For e-mail address protection with recaptcha for postfix.
If somebody send an e-mail to a protected address the MailCaptcha defer it with 4xx temporary failure and send an e-mail to the sender with the URL where the sender can solve the captcha and get their e-mail address to the whitelist. After that the mail system is accepting the e-mail address.
There is a
- whitelist (you can put e-mail address or only domain in it without @)
- blacklist (you can put e-mail address or only domain in it without @)
- honeypot e-mail list (you can put e-mail address or only domain in it without @)
- notification to the mail system administrator
- sent mail can be signed with x.509 certificate
Requirements
- web2py 1.99.7 (http://web2py.com)
- postfix (http://postfix.com)
What does this?
- somebody send you an email from somebody@domain.com
- postfix ask MailCaptcha what to do
- if the recipient address is not in the protected list do nothing special
- else if the sender is in the blacklist reject the message with 5xx code
- else if the recipient address is a honeypot address put the sender in the blacklist and reject the message with 5xx code
- else if the sender is in the whitelist do nothing special
- else if the sender is in the waiting queue the message get a temporary rejection with 4xx code
- else if the sender is not in queue then
. put the sender address in the waiting queue
. send a mail to the sender address with the web url where the sender can solve the captcha and so the sender address is going to the whitelist
. optionally send a mail to mail system admin to notify about a new sender address in the waiting queue so admin can enable the sender address by hand - the sender have to go to the web url and solve the captcha
- sender address is going to the whitelist
- the next time the sender's mail system (the system that hold the sender's mail) try to deliver the e-mail after temporary failure can deliver the message without problem
Credit
The main idea is from: http://www.kfki.hu/cnc/projekt/postfilter/indexeng.html http://www.kfki.hu/cnc/projekt/postfilter/docs/README.txt
József Kadlecsik
together with the members of "CSI-KO Csillebérci Komputer" Company.