Date: December 5, 2009

Pingpong
========

 Pingpong is just my (Daniel's) jestful collective name on the protocols that
 share a very similar kind of back-and-forth procedure with command and
 responses to and from the server. FTP was previously the only protocol in
 that family that libcurl supported, but when POP3, IMAP and SMTP joined the
 team I moved some of the internals into a separate pingpong module to be
 easier to get used by all these protocols to reduce code duplication and ease
 code re-use between these protocols.

FTP

 In 7.20.0 we converted code to use the new pingpong code from previously
 having been all "native" FTP code.

POP3

 There's no support in the documented URL format to specify the exact mail to
 get, but we support that as the path specified in the URL.

IMAP

SMTP

 There's no official URL syntax defined for SMTP, but we use only the generic
 one and we provide two additional libcurl options to specify receivers and
 sender of the actual mail.