questions about using c-client

[DavidDDaveg]

- In the "internal.txt" there is a section of "Main Program Callbacks". If c-client is used for implementing a imap client, are all of the these mm_xxx callbacks required to be implemented, or could be selective?   - My understanding for using c-client is: use mail_xxx to send request to host imap server, and result will be put into the "MAILSTREAM *stream" for that mail box. Is there documentation about how to extract the result for the interested request. i.e. listing sub folders; listing mails in the folders;   -Is the member "unsigned long nmsgs;  /* # of associated msgs */" of mail_stream represents all mails in this mailbox (including mails inside sub folders), or only top level mails?   -In mail_stream:   unsigned long nmsgs;  /* # of associated msgs */   unsigned long recent;   /* # of recent msgs */ Should they be  same when that mailbox is open?   - After did mail_open() for a mail box, the returned "stream" will represent this mail box. Will all of the consequent request against this mail box (i.e. mail_fetchstructure(); mail_recent();..) using same under line socket, or a new socket will be open for each request?   -What is the difference between stream->tcpsi and stream->tcpso?   Thanks for your help!