Some things a client must do and how to do them with C-client:

Connect to a server

Handled by mail_open. See Mailbox Access Functions for a description of the function. To specify the server you want to connect to, you put in in the mailbox name as shown in Mailbox Name Conventions. C-client supports many protocols, but defaults to IMAP if you specify a server hostname. If you're not sure what folder to open (i.e., you're connecting to the server to get an initial list of folders) use INBOX -- I think that's always there.

Log in / Authenticate

Automatically handled by c-client. It will use a callback to let the program know when it needs a username and password

Some links on IMAP client stuff.

• C-Client documentation
  • a partially HTML-ified and possibly out-of-date version
• Mailbox Naming Conventions tells how to format the mailbox name that you give to the mail_open function to specify the protocol and server you are using
• C-Client "driver" info
• C-Client mailing-list
• RFC 2683: IMAP4 Implementation Recommendations

The sections most relevant to a beginner client writer are Mailbox Access Functions and Main Program Callbacks (note: these are from the possibly-out-of-date page mentioned above)

IMAP protocol specifications

• RFC3501 -- IMAP 4rev1
• RFC2061 -- the old IMAP 4rev1 specification
• RFC2342 -- IMAP Namespace extension
• RFC2359 -- IMAP4 UIDPLUS extension

Information on the latest updates of the IMAP standard

Informational RFCs about IMAP

• RFC2683 -- "IMAP4 Implementation Recommendations"
• RFC2180 -- "IMAP4 Multi-Accessed Mailbox Practice

libEtPan a new C IMAP library, it aims to be easier to use than C-client.

Relevant books

• Internet Email Protocols: A Developer's Guide
• Programming Internet Email focuses on Java and Perl programming