无法在其他电子邮件服务提供商上呈现Outlook邀请

Question

我正在使用Java邮件向四个不同的电子邮件服务器发送一个Outlook邀请：

web.de
gmx.net
gmail.com
company's private email server (which is configured on outlook)

邀请仅在gmail上呈现/预览，但我们需要在每个平台上呈现/预览。

我的主要课程是

public class Email {

// Constants for the ICalendar methods.
public static final String METHOD_CANCEL = "CANCEL";
public static final String METHOD_PUBLISH = "PUBLISH";
public static final String METHOD_REQUEST = "REQUEST";
// Apply this organizer, if no organizer is given.
private static final String DEFAULT_ORGANIZER = "zain@company.com";
// Common ICalendar fields.
private String method;
private Calendar beginDate;
private Calendar endDate;
private String location;
private int uid;
private String description;
private String subject;
private String organizer;

/*
* @param args
*/
public static void main(String[] args) {
try {
Email email = new Email();
email.send();
} catch (Exception e) {
e.printStackTrace();
} finally {
System.exit(0);
}
}

public void send() throws Exception {
try {
String from = "mansoor@company.com";
Properties prop = new Properties();

Address[] receivers = new InternetAddress[] {
new InternetAddress("abc@company.com")
, new InternetAddress("abc@gmail.com")
, new InternetAddress("abc@web.de")
, new InternetAddress("abc@gmx.de")
};

prop.put("mail.transport.protocol", "smtp");
prop.put("mail.smtp.host", "smtp.company.com");
prop.put("mail.smtp.port", "587");
prop.put("mail.smtp.auth", "true");
Authenticator authenticator = new Authenticator() {
protected PasswordAuthentication getPasswordAuthentication() {
return new PasswordAuthentication("smtp@company.com", "password");
}
};

Session session = Session.getDefaultInstance(prop, authenticator);
// Define message
MimeMessage message = new MimeMessage(session);
message.addHeaderLine("method=REQUEST");
message.addHeaderLine("charset=UTF-8");
message.addHeaderLine("component=VEVENT");
message.setFrom(new InternetAddress(from));
message.addRecipients(Message.RecipientType.TO, receivers);
message.setSubject("Outlook Meeting Request Using JavaMail");

this.subject = "Meeting Request Test Subject";
this.description = "PLEASE IGNORE THIS MAIL AS IT IS A TEST.";
this.beginDate = new GregorianCalendar(2018, 07-01, 17, 19, 00);
this.endDate = new GregorianCalendar(2018, 07-01, 17, 19, 45);
this.method = Email.METHOD_REQUEST;
this.location = "Office # 13";

// Create the calendar part
BodyPart calendarPart = new MimeBodyPart();
// Fill the message
calendarPart.setHeader("Content-Class", "urn:content-  classes:calendarmessage");
calendarPart.setHeader("Content-ID", "calendar_message");
calendarPart.setHeader("Content-Disposition", "inline;filename=Test_invite1.ics");
calendarPart.setFileName("Test_invite1");
calendarPart.setDataHandler(
new DataHandler(
new ByteArrayDataSource(createMessage(), "text/calendar")));// very important

// Create a Multipart
Multipart multipart = new MimeMultipart();
// Add part one
multipart.addBodyPart(calendarPart);

// Put parts in message
message.setContent(multipart);

// send message
Transport.send(message);

for(Address receiver: receivers){
System.out.println(receiver);
}

} catch (MessagingException me) {
System.out.println("Failed sending email");
me.printStackTrace();
} catch (Exception ex) {
System.out.println("Failed sending email");
ex.printStackTrace();
} finally {
System.out.println("End sending email");
System.exit(0);
}
}

public String createMessage() {
// Create the proper date format string required by the ICalendar spec.
final SimpleDateFormat formatter = new SimpleDateFormat("yyyyMMdd'T'HHmmss");
final String stringBeginDate = formatter.format(beginDate.getTime());
final String stringEndDate = formatter.format(endDate.getTime());
// Encode the description => mark new lines.
final String encodedDescription = description.replaceAll("\r\n", "\\\\n");
// Use the default organizer if none is given.
if (this.organizer == null) {
this.organizer = DEFAULT_ORGANIZER;
}
// Content string as array.
String[] contents = {
"BEGIN:VCALENDAR",
"METHOD:" + this.method,
"BEGIN:VEVENT",
"UID:" + this.uid,
"DTSTART:" + stringBeginDate,
"DTEND:" + stringEndDate,
"LOCATION:" + this.location,
"DESCRIPTION:" + encodedDescription,
"ATTENDEE;RSVP=TRUE:MAILTO:" + this.organizer,
"ORGANIZER:" + this.organizer,
"SUMMARY:" + this.subject,
"END:VEVENT",
"END:VCALENDAR"
};
// Build a well-formatted string from the array.
StringBuilder sb = new StringBuilder();
for (String line : contents) {
if (sb.length() > 0) {
sb.append("\n");
}
sb.append(line);
}
return sb.toString();
}
}

如果不确定，请添加评论。我在stackoverflow.com上看到了很多问题，但找不到合适的解决方案。