.NET使用MailKit进行邮件处理的方法步骤
0.介绍
MimeKit and MailKit are popular fully-featured email frameworks for .NET
框架支持版本如下
Supports .NET 4.5, .NET 4.6, .NET 4.7, .NET 4.8, .NET 5.0, .NETStandard 2.0, Xamarin.Android, Xamarin.iOS, Windows Phone 8.1, and more.
MailKit是最流行且最强大的.NET邮件处理框架之一，下面为大家简单介绍MailKit的使用方式（IMAP为例）
1. 参考资料
Github https://github.com/jstedfast/MailKit
官方Doc http://www.mimekit.net/docs/html/Introduction.htm
2.核心内容（IMAP为例）
连接邮箱
加密
client.Connect("imap.exmail.qq.com", 993, SecureSocketOptions.SslOnConnect);
不加密
client.Connect("imap.exmail.qq.com", 143, SecureSocketOptions.None);
登入邮箱
client.Authenticate(MAIL_NAME, MAIL_PASSWORD);
打开邮件文件夹
client.Inbox.Open(FolderAccess.ReadWrite);
读取文件
读取方式一：可以预先筛选邮件
search for messages where the Subject header contains either "MimeKit" or "MailKit"
var query = SearchQuery.SubjectContains("MimeKit").Or(SearchQuery.SubjectContains("MailKit"));
var uids = client.Inbox.Search(query);
读取方式二：读取所有邮件
var uids = client.Inbox.Search(SearchQuery.All);
邮件操作
操作邮件一：读取邮件标题
string subject = message.Subject;
if (!subject.Contains("MimeKitDemo"))
return;
操作邮件二：读取正文
string body = message.TextBody ?? string.Empty;
if (!body.Contains("MimeKitDemoBody"))
return;
操作邮件三：下载邮件附件
var attachments = message.Attachments;
if (attachments.Any())
{
foreach (var attachment in attachments)
DownloadAttachment(attachment);
}
private static void DownloadAttachment(MimeEntity attachment)
{
if (attachment is MessagePart)
{
var fileName = attachment.ContentDisposition?.FileName;
var rfc822 = (MessagePart)attachment;
if (string.IsNullOrEmpty(fileName))
fileName = "attached-message.eml";
var path = Path.Combine(DIRECTORY, fileName);
using (var stream = File.Create(path))
rfc822.Message.WriteTo(stream);
}
else
{
var part = (MimePart)attachment;
var fileName = part.FileName;
var path = Path.Combine(DIRECTORY, fileName);
using (var stream = File.Create(path))
part.Content.DecodeTo(stream);
}
}
操作邮件四：移动邮件（移动至删除文件夹）
client.Inbox.MoveTo(uid, client.GetFolder(SpecialFolder.Trash));
操作邮件五：删除邮件 - 将邮件标记为删除、最后删除
client.Inbox.AddFlags(uid, MessageFlags.Deleted, true); client.Inbox.Expunge();