c# 利用MailKit.IMap 收取163邮件

最近我要做一个爬虫。这个爬虫需要如下几个步骤：

1 填写注册内容(需要邮箱注册)

2 过拖拽验证码(geetest)

3 注册成功会给邮箱发一封确认邮箱

4 点击确认邮箱中的链接 完成注册

我这里就采用163邮箱注册。

邮箱协议有 pop3 和 imap 和 smtp

我试了pop3  不能够筛选邮件 例如筛选未读 和 发件人这2个条件 所以放弃用pop3

imap协议是支持的。

我就找了一个开源的第三方lib：S22.Imap

用法很简单:

public void Test163()
        {
            var imapServer = "imap.163.com";
            var port = 993;
            using (ImapClient client = new ImapClient(imapServer, port, "xxxx@163.com", "pwd", AuthMethod.Login, true))
            {
                // Returns a collection of identifiers of all mails matching the specified search criteria.
                IEnumerable<uint> uids = client.Search(SearchCondition.Unseen());
                // Download mail messages from the default mailbox.
                IEnumerable<MailMessage> messages = client.GetMessages(uids,FetchOptions.HtmlOnly);

                Console.WriteLine("We are connected!");
            }

        }

发现 在login的时候 报错了：

提示“NO Select Unsafe Login. Please contact kefu@188.com for help”。

163邮箱也会收到一个告警邮件

经过查证 发现得需要在发送 login 命令之前 得先发送 id 命令

至于为什么要这么做 我的理解是得先伪装成普通的客户端吧(有理解错误请指出谢谢)

我fork了一份SS2.imap的代码 打算兼容163的这个特殊情况改掉源码

然后走Login方法就不会报错了

Github地址：https://github.com/yuzd/S22.Imap

http://www.mimekit.net/docs/html/M_MailKit_Net_Imap_ImapClient_Identify.htm

public static void Capabilities ()
{
    using (var client = new ImapClient ()) {
        client.Connect ("imap.gmail.com", 993, SecureSocketOptions.SslOnConnect);

        var mechanisms = string.Join (", ", client.AuthenticationMechanisms);
        Console.WriteLine ("The IMAP server supports the following SASL authentication mechanisms: {0}", mechanisms);

        client.Authenticate ("username", "password");

        if (client.Capabilities.HasFlag (ImapCapabilities.Id)) {
            var clientImplementation = new ImapImplementation { Name = "MailKit", Version = "1.0" };
            var serverImplementation = client.Identify (clientImplementation);

            Console.WriteLine ("Server implementation details:");
            foreach (var property in serverImplementation.Properties)
                Console.WriteLine ("  {0} = {1}", property.Key, property.Value);
        }

        if (client.Capabilities.HasFlag (ImapCapabilities.Acl)) {
            Console.WriteLine ("The IMAP server supports Access Control Lists.");

            Console.WriteLine ("The IMAP server supports the following access rights: {0}", client.Rights);

            Console.WriteLine ("The Inbox has the following access controls:");
            var acl = client.Inbox.GetAccessControlList ();
            foreach (var ac in acl)
                Console.WriteLine ("  {0} = {1}", ac.Name, ac.Rights);

            var myRights = client.Inbox.GetMyAccessRights ();
            Console.WriteLine ("Your current rights for the Inbox folder are: {0}", myRights);
        }

        if (client.Capabilities.HasFlag (ImapCapabilities.Quota)) {
            Console.WriteLine ("The IMAP server supports quotas.");

            Console.WriteLine ("The current quota for the Inbox is:");
            var quota = client.Inbox.GetQuota ();

            if (quota.StorageLimit.HasValue && quota.StorageLimit.Value)
                Console.WriteLine ("  Limited by storage space. Using {0} out of {1} bytes.", quota.CurrentStorageSize.Value, quota.StorageLimit.Value);

            if (quota.MessageLimit.HasValue && quota.MessageLimit.Value)
                Console.WriteLine ("  Limited by the number of messages. Using {0} out of {1} bytes.", quota.CurrentMessageCount.Value, quota.MessageLimit.Value);

            Console.WriteLine ("The quota root is: {0}", quota.QuotaRoot);
        }

        if (client.Capabilities.HasFlag (ImapCapabilities.Thread)) {
            if (client.ThreadingAlgorithms.Contains (ThreadingAlgorithm.OrderedSubject))
                Console.WriteLine ("The IMAP server supports threading by subject.");
            if (client.ThreadingAlgorithms.Contains (ThreadingAlgorithm.References))
                Console.WriteLine ("The IMAP server supports threading by references.");
        }

        client.Disconnect (true);
    }
}