我可以使用MailKit通过电子邮件发送文件吗？

Question

作为标题,MailKit是否支持发送文件？
如果是,我该怎么办？

Answer 1

是.这在文档和FAQ中有解释.

来自FAQ:

如何创建带附件的邮件？

要构造带附件的消息,首先需要创建一个multipart/mixed 容器,然后您需要先将消息体添加到容器中.添加完正文后,您可以添加包含您要附加​​的文件内容的MIME部分,并确保将Content-Disposition标题值设置为附件.您可能还想filename 在Content-Disposition标题上设置参数以及标题上的name参数Content-Type .最方便的方法是简单地使用MimePart.FileName属性,该 属性将为您设置两个参数,并将Content-Disposition标头值attachment 设置为尚未设置为其他值.

var message = new MimeMessage ();
message.From.Add (new MailboxAddress ("Joey", "joey@friends.com"));
message.To.Add (new MailboxAddress ("Alice", "alice@wonderland.com"));
message.Subject = "How you doin?";

// create our message text, just like before (except don't set it as the message.Body)
var body = new TextPart ("plain") {
    Text = @"Hey Alice,

What are you up to this weekend? Monica is throwing one of her parties on
Saturday and I was hoping you could make it.

Will you be my +1?

-- Joey
"
};

// create an image attachment for the file located at path
var attachment = new MimePart ("image", "gif") {
    Content = new MimeContent (File.OpenRead (path)),
    ContentDisposition = new ContentDisposition (ContentDisposition.Attachment),
    ContentTransferEncoding = ContentEncoding.Base64,
    FileName = Path.GetFileName (path)
};

// now create the multipart/mixed container to hold the message text and the
// image attachment
var multipart = new Multipart ("mixed");
multipart.Add (body);
multipart.Add (attachment);

// now set the multipart/mixed as the message body
message.Body = multipart;

使用附件构造消息的一种更简单的方法是利用 BodyBuilder类.

var message = new MimeMessage ();
message.From.Add (new MailboxAddress ("Joey", "joey@friends.com"));
message.To.Add (new MailboxAddress ("Alice", "alice@wonderland.com"));
message.Subject = "How you doin?";

var builder = new BodyBuilder ();

// Set the plain-text version of the message text
builder.TextBody = @"Hey Alice,

What are you up to this weekend? Monica is throwing one of her parties on
Saturday and I was hoping you could make it.

Will you be my +1?

-- Joey
";

// We may also want to attach a calendar event for Monica's party...
builder.Attachments.Add (@"C:\Users\Joey\Documents\party.ics");

// Now we just need to set the message body and we're done
message.Body = builder.ToMessageBody ();

有关更多信息,请参阅创建消息.

Answer 2

@jstedfast 带来了非常酷的解决方案，这里有一些简单的方法示例，可以将文件作为附件发送（在这种情况下为 pdf 文档，但可以应用于任何文件类型）。

var message = new MimeMessage();
// add from, to, subject and other needed properties to your message

var builder = new BodyBuilder();
builder.HtmlBody = htmlContent;
builder.TextBody = textContent;

// you can either create MimeEntity object(s)
// this might get handy in case you want to pass multiple attachments from somewhere else
byte[] myFileAsByteArray = LoadMyFileAsByteArray();
var attachments = new List<MimeEntity>
{
    // from file
    MimeEntity.Load("myFile.pdf"),
    // file from stream
    MimeEntity.Load(new MemoryStream(myFileAsByteArray)),
    // from stream with a content type defined
    MimeEntity.Load(new ContentType("application", "pdf"), new MemoryStream(myFileAsByteArray))
}

// or add file directly - there are a few more overloads to this
builder.Attachments.Add("myFile.pdf");
builder.Attachments.Add("myFile.pdf", myFileAsByteArray);
builder.Attachments.Add("myFile.pdf", myFileAsByteArray , new ContentType("application", "pdf"));

// append previously created attachments
foreach (var attachment in attachments)
{
    builder.Attachments.Add(attachment);
}

message.Body = builder.ToMessageBody();

希望能帮助到你。