Iam learning java for few months.And i plan to
write a java mail server program
and chatting program which serve the following
features:

Java Mail Server:
"Supports MIME.An address book feature provides way
to store mail
addresses.Received messages can be transfered to
custom defined
folders.Alais name can be given to a group of
addresses to ease
group mailing.The user can block particular mail
addresses to stop
receiving mail from those addresses.Once connected
to the server,
other users connected to the mail server can be
known."

Java Chatting:
"Multiple Clients can be connected to the Server
and
can chat simultaneously.The chat message can be
saved.
A user can manage a friends list.Upon connecting to
the
server,a user will know the persons who are all
connected
to the server.A user can block another user to
avoid
messages from that user."

In the case of chatting program, where to store the
friend's list
and other details. Can i be able to store them in a
file or should
i use backend.

In the case of Java mail server, what should i do
to support MIME.
What about the storage details of address
list,mails etc., is a back end
unavoidable.

Please help me how to approach these 2 problems.How
long will it take to
write them.What all in java i should learn to write
these.If u have any sample
programs or materials or links, please send them to
me as it would help me a lot.