Functions in IMAP, POP3 AND LDAP?

ans:

These functions are not limited to the IMAP protocol, despite their name. The underlying c-client library also supports NNTP, POP3 and local mailbox access methods.

Requirements
This extension requires the c-client library to be installed. Grab the latest version from ftp://ftp.cac.washington.edu/imap/ and compile it.

It's important that you do not copy the IMAP source files directly into the system include directory as there may be conflicts. Instead, create a new directory inside the system include directory, such as /usr/local/imap-2000b/ (location and name depend on your setup and IMAP version), and inside this new directory create additional directories named lib/ and include/. From the c-client directory from your IMAP source tree, copy all the *.h files into include/ and all the *.c files into lib/. Additionally when you compiled IMAP, a file named c-client-a was created. Also put this in the lib/ directory but rename it as libc-client.a.

Note: To build the c-client library with SSL or/and Kerberos support read the docs supplied with the package.

Installation
To get these functions to work, you have to compile PHP with --with-imap[=DIR], where DIR is the c-client install prefix. From our example above, you would use --with-imap=/usr/local/imap-2000b. This location depends on where you created this directory according to the description above. Windows users may include the php_imap.dll DLL in php.ini