看到C#中调用Outlook API 发起会议 ，这个完全可以用SMTP方式实现的，下面我的项目中使用的代码：
对于.NET而言，从2.0开始，发邮件已经是一件非常容易的事了。而且新增了一个AlternateView，使用 AlternateView 类可以指定一个电子邮件的不同格式副本。例如，如果您发送 HTML 格式的邮件，您可能希望同时提供邮件的纯文本格式，以防一些收件人使用的电子邮件阅读程序无法显示HTML 内容。
通过使用AlternateView我们就可以实现Exchange 会议邮件的发送。核心代码如下：
MailMessage msg = new MailMessage();
// Set up the different mime types contained in the message
System.Net.Mime.ContentType textType = new System.Net.Mime.ContentType("text/plain");
System.Net.Mime.ContentType HTMLType = new System.Net.Mime.ContentType("text/html");
System.Net.Mime.ContentType calendarType = new System.Net.Mime.ContentType("text/calendar");
// Add parameters to the calendar header
calendarType.Parameters.Add("method", "REQUEST");
calendarType.Parameters.Add("name", "meeting.ics");
// Create message body parts
// create the Body in text format
string bodyText = "Type:Single Meeting"r"nOrganizer: {0}"r"nStart Time:{1}"r"nEnd Time:{2}"r"nTime Zone:{3}"r"nLocation: {4}"r"n"r"n*~*~*~*~*~*~*~*~*~*"r"n"r"n{5}";
bodyText = string.Format(bodyText, organizerName, start.ToLongDateString() + " " + start.ToLongTimeString(), end.ToLongDateString() + " " + end.ToLongTimeString(), System.TimeZone.CurrentTimeZone.StandardName, location, summary);
AlternateView textView = AlternateView.CreateAlternateViewFromString(bodyText, textType);
msg.AlternateViews.Add(textView);
//create the Body in HTML format
string bodyHTML = "<!DOCTYPE HTML PUBLIC ""-//W3C//DTD HTML 3.2//EN"">"r"n<HTML>"r"n<HEAD>"r"n<META HTTP-EQUIV=""Content-Type"" CONTENT=""text/html; charset=utf-8"">"r"n<META NAME=""Generator"" CONTENT=""MS Exchange Server version 6.5.7652.24"">"r"n<TITLE>{0}</TITLE>"r"n</HEAD>"r"n<BODY>"r"n<!-- Converted from text/plain format -->"r"n<P><FONT SIZE=2>Type:Single Meeting<BR>"r"nOrganizer:{1}<BR>"r"nStart Time:{2}<BR>"r"nEnd Time:{3}<BR>"r"nTime Zone:{4}<BR>"r"nLocation:{5}<BR>"r"n<BR>"r"n*~*~*~*~*~*~*~*~*~*<BR>"r"n<BR>"r"n{6}<BR>"r"n</FONT>"r"n</P>"r"n"r"n</BODY>"r"n</HTML>";
bodyHTML = string.Format(bodyHTML,summary,organizerName,start.ToLongDateString() + " " + start.ToLongTimeString(),end.ToLongDateString() + " " + end.ToLongTimeString(),System.TimeZone.CurrentTimeZone.StandardName,location,summary);
AlternateView HTMLView = AlternateView.CreateAlternateViewFromString(bodyHTML, HTMLType);
msg.AlternateViews.Add(HTMLView);
//create the Body in VCALENDAR format
string calDateFormat = "yyyyMMddTHHmmssZ";
string bodyCalendar = "BEGIN:VCALENDAR"r"nMETHOD:REQUEST"r"nPRODID:Microsoft CDO for Microsoft Exchange"r"nVERSION:2.0"r"nBEGIN:VTIMEZONE"r"nTZID:(GMT-06.00) Central Time (US & Canada)"r"nX-MICROSOFT-CDO-TZID:11"r"nBEGIN:STANDARD"r"nDTSTART:16010101T020000"r"nTZOFFSETFROM:-0500"r"nTZOFFSETTO:-0600"r"nRRULE:FREQ=YEARLY;WKST=MO;INTERVAL=1;BYMONTH=11;BYDAY=1SU"r"nEND:STANDARD"r"nBEGIN:DAYLIGHT"r"nDTSTART:16010101T020000"r"nTZOFFSETFROM:-0600"r"nTZOFFSETTO:-0500"r"nRRULE:FREQ=YEARLY;WKST=MO;INTERVAL=1;BYMONTH=3;BYDAY=2SU"r"nEND:DAYLIGHT"r"nEND:VTIMEZONE"r"nBEGIN:VEVENT"r"nDTSTAMP:{8}"r"nDTSTART:{0}"r"nSUMMARY:{7}"r"nUID:{5}"r"nATTENDEE;ROLE=REQ-PARTICIPANT;PARTSTAT=NEEDS-ACTION;RSVP=TRUE;CN=""{9}"":MAILTO:{9}"r"nACTION;RSVP=TRUE;CN=""{4}"":MAILTO:{4}"r"nORGANIZER;CN=""{3}"":mailto:{4}"r"nLOCATION:{2}"r"nDTEND:{1}"r"nDESCRIPTION:{7}""N"r"nSEQUENCE:1"r"nPRIORITY:5"r"nCLASS:"r"nCREATED:{8}"r"nLAST-MODIFIED:{8}"r"nSTATUS:CONFIRMED"r"nTRANSP:OPAQUE"r"nX-MICROSOFT-CDO-BUSYSTATUS:BUSY"r"nX-MICROSOFT-CDO-INSTTYPE:0"r"nX-MICROSOFT-CDO-INTENDEDSTATUS:BUSY"r"nX-MICROSOFT-CDO-ALLDAYEVENT:FALSE"r"nX-MICROSOFT-CDO-IMPORTANCE:1"r"nX-MICROSOFT-CDO-OWNERAPPTID:-1"r"nX-MICROSOFT-CDO-ATTENDEE-CRITICAL-CHANGE:{8}"r"nX-MICROSOFT-CDO-OWNER-CRITICAL-CHANGE:{8}"r"nBEGIN:VALARM"r"nACTION:DISPLAY"r"nDESCRIPTION:REMINDER"r"nTRIGGER;RELATED=START:-PT00H15M00S"r"nEND:VALARM"r"nEND:VEVENT"r"nEND:VCALENDAR"r"n";
bodyCalendar = string.Format(bodyCalendar,start.ToUniversalTime().ToString(calDateFormat),end.ToUniversalTime().ToString(calDateFormat),location,organizerName,organizerEmail,Guid.NewGuid().ToString("B"),summary,subject,DateTime.Now.ToUniversalTime().ToString(calDateFormat),attendeeList.ToString());
AlternateView calendarView = AlternateView.CreateAlternateViewFromString(bodyCalendar, calendarType);
calendarView.TransferEncoding = TransferEncoding.SevenBit;
msg.AlternateViews.Add(calendarView);
// Address the message
msg.From = new MailAddress(organizerEmail);
foreach (MailAddress attendee in attendeeList)
{
msg.To.Add(attendee);
}
msg.Subject = subject;
return msg;
http://rongchaua.net/blog/sharepoint-send-appointment-without-using-outlook-object/
