IspCP Autoreply infinite autoreplies loop

[kilburn]

The current ispcp's autoreplier is prone to enter an "infinite autoreply" loop when an address with autoreply enabled sends an e-mail to another autoreply-enabled address.

Although the current script checks some special headers trying to detect this kind of loops, it's not enough when the other (not ispcp-controlled) autoreplier deletes such headers in their replies.

See  this thread for evidence.

[kilburn]

Fixed in r2592.

To solve it, I've created a new "autoreplies_log" table, storing <time,from,to> records of all the sent autoreplies. Thereafter, the logic goes as follows:

• arpl start
• delete autoreplies_log records older than 24 hours
• before sending a message, check if there exists a record with the same <from,to> than the one we are about to send, and:
  • If the record exist, skip sending the autoreply.
  • Otherwise (1) send the message, (2) add a new record <now(),from,to>