无法通过 MailKit 发送带有图像附件 iCal.net

Question

我正在尝试发送一个通过 iCal.net 生成的.ics文件。在Outlook中打开文件很好，并且具有我尝试通过MailKit发送的图像附件，但是通过Mailkit发送时，图像不存在。

开始：万历 方式：请求 PRODID：-//github.com/rianjs/ical.net//NONSGML ical.net 4.0//EN 版本：2.0 开始：万事 附加;FMTTYPE=image/png;X-文件名=qrcode.png;值=二进制;编码=基数6 4：iVBORw0KGgoAAAANSUhEUgAABkAAAAZAAQMAAAAbwhzkAAAABGdBTUEAALGPC/xhBQAAAAF zUkdCAK7OHOkAAAAGUExURQAAAP7+/soH9D0AAAYwSURBVHja7dyxcYNAEAVQPA4UugRKoTRc GqW4BIcKNMKBcABzXu8JhIXn/UwSJ/Zt/Oea8Z+kAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBA QEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQE EBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBA BAQEBAXkiyGdTn77iaHt79nLHa1oQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQE EBAQEBAQEBAQEJA9IC+ZVvolhHS3b88hpE+130FAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQE EBAQEBAQEBAQEBAQEBAQEBAQEBAQP4AMmQK7vNpruVme80OppxAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQE BAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQECOCeluH1PdeBAQEBAQEBAQEBAQEBAQEBAQEBAQEBA QEBAQEBAQEBAQEBAQEBAQEBAQEBAQKGND4pvaQUBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBA QEBAQEBAQEBAQEBAQEBADgYJE0OG+TTh0TggICAgICAgICAgICAgICAgICAgICAgI CAgICAgICAgICAgICAgICAgICB7QqqSgpS78TUBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQE EBAQEBAQEBAQEBAQEBAQEBAQEF5LGRF4h2MjwoICAgICAgICAg ICAgICAgICAgICAgICAgICMhGkPI0izvTP6Ju/IosLnk/b1/yBwEBAQEBAQEBAQEBAQEBAQEB AQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEB+RVyz1+mdjDlEu6gW4wKAgICAgICAgICAgICA gICAgICAgICAgICAgICAgKyB6Scc1hp76MdjCGk3I0f5jsAAQEBAQ EBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQHZBRJ348PhYkhNrb6rWTI ICAgICAgICAgICAgICAgICMi2kB8yPfTRJFKe pnz07fbjdX40tT4QEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBA JCtICuSqtWndjDllHotCAgICAgICAgICAgICA gICAjIRpDPpj797B+umSOv08PvGcj0sQUBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBA BAQEBAQEBAQEBAQEBAdkD8pJppV/mkMXRYT5VuRtf3kFXU8kHAQEBAQEBAQEBAQEBAQEBAQEB AQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEF5DGQoltbbImQxzYpMkMVN7SAgICAgICAgICAgICAgI CAgICAgICAgICAgIAeDnMZEype8p46CgICAgICAgICAgICAgI CAgICAgICAgICAgIA8AeSem9pr0oKAgICAgICAgICA AgICAgICAgICAgICAgICAgICAgOwJSU0zh3ynW7yvOM17ceRurAgICAgI CAgICAgICAgICAgICAgICMi2kKr00dFTZgdTrjU7A AEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEB2RhyvICAgICAgI CAgICAgICAgICAgICA AgICAgICAgICAg gICAgICAgICAgICAgICAgICAgICArMkXJlylJdANIpEAAAAASUVORK5CYILyxAyAPDEDI E/MAMgTMwDyxAyAPDEDIE/MAMgTMwDyxAyAPDEDIE/MAMgTMwDyxAyAvDnnbM/wVjPz8rNbZ/ VpM98ofs/F97vFWfF33MwAyBMzAPLEDIA8MQMgT8wAyBMzAPLEDIA8MQMgT8wAyBMzAPLEDIA 8MQMgT8wAyBMzAPLEDIA8MQMgT8wAyBMzAPLEDIC8Z2vhmdlaesXNfs85K+veKM7sm/zdir+F G1v/OVvczADIEzMA8sQMgDwxAyBPzADIEzMA8sQMgDwxAyBPzADIEzMA8sQMgDwxAyBPzADIE zMA8sQMgDwxAyBPzADIEzMA8sQMgLw552zPwC80Myvrbn3PN/st/gbt9+tu9vtp695wMwMgT8 wAyBMzAPLEDIA8MQMgT8wAyBMzAPLEDIA8MQMgT8wAyBMzAPLEDIA8MQMgT8wAyBMzAPLEDIA 8MQMgT8wAyBMzAPKerYVnZmtpvuics/Lsp30bW/u9eUdbbs5qa7/FmYvczADIEzMA8sQMgDwx AyBPzADIEzMA8sQMgDwxAyBPzADIEzMA8sQMgDwxAyBPzADIEzMA8sQMgDwxAyBPzADIEzMA8 sQMgLxne4BXnHO2R8iYGev+cDff881+P+2stpj5PdzMAMgTMwDyxAyAPDEDIE/MAMgTMwDyxA yAPDEDIE/MAMgTMwDyxAyAPDEDIE/MAMgTMwDyxAyAPDEDIE/MAMgTMwDyxAyAvGd7gHebme0 Rvu2csz3Ct93MfPOOimdV/CZv2O/XbX3PxZndzADIEzMA8sQMgDwxAyBPzADIEzMA8sQMgDwx AyBPzADIEzMA8sQMgDwxAyBPzADIEzMA8sQMgDwxAyBPzADIEzMA8sQMgLxnewD4q3POy8/Oz Mq6vMfWt7Fla+bib8HNDIA8MQMgT8wAyBMzAPLEDIA8MQMgT8wAyBMzAPLEDIA8MQMgT8wAyB MzAPLEDIA8MQMgT8wAyBMzAPLEDIA8MQMgT8wAyHu2B+B3mpntEb7tZuZzzsqzN4rv6MbNOW9 9GzduZi7u180MgDwxAyBPzADIEzMA8sQMgDwxAyBPzADIEzMA8sQMgDwxAyBPzADIEzMA8sQM gDwxAyBPzADIEzMA8sQMgDwxAyBPzADIe7YHeLdzzvYI/EHF9zszLz9b3O+Wm3Mu+rRvw80Mg DwxAyBPzADIEzMA8sQMgDwxAyBPzADIEzMA8sQMgDwxAyBPzADIEzMA8sQMgDwxAyBPzADIEz MA8sQMgDwxAyBPzADIe7YHeMXMbI/AH3TOWVn3076rm3O+OaviujfM/B5uZgDkiRkAeWIGQJ6 YAZAnZgDkiRkAeWIGQJ6YAZAnZgDkiRkAeWIGQJ6YAZAnZgDkiRkAeWIGQJ6YAZAnZgDkiRkA eWIGQN6cc7ZnAIArbmYA5IkZAHliBkCemAGQJ2YA5IkZAHliBkCemAGQJ2YA5IkZAHliBkCem AGQJ2YA5IkZAHliBkCemAGQJ2YA5IkZAHliBkCemAGQJ2YA5IkZAHliBkCemAGQJ2YA5IkZAH liBkCemAGQJ2YA5IkZAHliBkCemAGQJ2YA5IkZAHliBkCemAGQJ2YA5IkZAHliBkDe/wB5w4S q9G4M2AAAAABJRU5ErkJggg== 与会者;CN=韦恩·李;PARTSTAT=REQ-PARTICIPANT;RSVP=TRUE：mailto：song.John@ company.com 类别：公共 描述：您好\，\我们希望您喜欢您的访问 电话：20190723T183343 邮票：20190723T153343Z 启动时间：20190723T173343 地理：52.051681;-4.283453 地点：法国主办单位;CN=韦恩 Lee:mailto:[e-mail] 序列：0 摘要：面试 传输：透明 UID：b9fb0c3e-728c-4121-912e-9412885ebbb4开始：报警 动作：显示 摘要：1小时前发出警报 触发：-PT1H 结束：报警 结束：万事 结束：万历

然后尝试使用以下代码发送：

var ical = new TextPart("calendar")
{
ContentTransferEncoding = ContentEncoding.Default,
ContentDisposition = new ContentDisposition (ContentDisposition.Inline),
Text = calendar
};
ical.ContentType.Parameters.Add("method", "REQUEST");
message.Body = ical;    

任何帮助将不胜感激。

谢谢

日历邀请对我来说很好，可以接受/拒绝等，但通过电子邮件，附件没有显示。

Answer 1

根据我从 Outlook 发送给自己的示例会议请求，Outlook 不会向text/calendar部分添加Content-Disposition。

它还对 base64 进行编码。

试试这个：

var ical = new TextPart("calendar")
{
ContentTransferEncoding = ContentEncoding.Base64,
Text = calendar
};
ical.ContentType.Parameters.Add("method", "REQUEST");

我还注意到，Outlook 倾向于使用以下结构(可能需要也可能不需要)构造 MIME 邮件：

multipart/alternative
text/plain
text/html
text/calendar