The Solid POP3 Server is an implementation of a Post Office Protocol version 3
server that has flexibility as its main goal. The server is easily configurable
and has support for few features such as:

- APOP authentication scheme
- virtual hosting
- maildir and mailbox handling
- bulletins
- expiration of messages

Each user can specify his maildrop (its position and type). The format used in
specification of maildrop's position should handle almost all widely-used
system configurations. The server also seems to be fast, however no tests have
been performed, so it's rather relative feeling. The design used is very
similar to the design of Solar Designer's POPA3D server. This solution let's
minimalize size of code working with root privileges. The code was also heavily
checked for buffer overflow leaks and file races. None have been found as for
now. All operations on files are done with user privileges. There is no SUID
APOP secrets database management program (as in QPOP). Each user can specify
his secret in his own home directory.

WWW: http://solidpop3d.pld.org.pl/