Question

I’m trying to get a list of mailboxes using AE.Net.Mail and I cannot find any documentation. The ListMailboxes method takes in a reference string and a pattern string. I’m not sure what either parameter should be.

using (var imap = new AE.Net.Mail.ImapClient(host, username, password, AE.Net.Mail.ImapClient.AuthMethods.Login, port, isSSL))
{
    List<Mailbox> boxes = imap.ListMailboxes("", ""); // string reference, string parameter
}

Answer 1

The ImapClient.ListMailboxes method from AE.Net.Mail is a pretty thin wrapper for the IMAP LIST command.

public Mailbox[] ListMailboxes(string reference, string pattern) 
{
    IdlePause();

    var x = new List<Mailbox>();
    string command = GetTag() + "LIST " + reference.QuoteString() + " " + pattern.QuoteString();
    string reg = "\\* LIST \\(([^\\)]*)\\) \\\"([^\\\"]+)\\\" \\\"?([^\\\"]+)\\\"?";
    string response = SendCommandGetResponse(command);
    Match m = Regex.Match(response, reg);
    while (m.Groups.Count > 1) 
    {
        Mailbox mailbox = new Mailbox(m.Groups[3].ToString());
        x.Add(mailbox);
        response = GetResponse();
        m = Regex.Match(response, reg);
    }
    IdleResume();
    return x.ToArray();
}

Section 6.3.8 of the IMAP RFC contains some examples of how these parameters are generally interpreted by the IMAP server ("Mailbox Name" is the pattern parameter):

Reference     Mailbox Name  Interpretation
------------  ------------  --------------
~smith/Mail/  foo.*         ~smith/Mail/foo.*
archive/      %             archive/%
#news.        comp.mail.*   #news.comp.mail.*
~smith/Mail/  /usr/doc/foo  /usr/doc/foo
archive/      ~fred/Mail/*  ~fred/Mail/*

Though it also says the following regarding the Reference parameter:

Note: The interpretation of the reference argument is
implementation-defined. It depends upon whether the
server implementation has a concept of the "current
working directory" and leading "break out characters",
which override the current working directory.

So the examples may or may not work depending on your server implementation.