Develop Reference

Exception when use EWS for create a appointment

I am get a exception when use my service EWS, this is my code
public class ExchangeHelper
{
ExchangeService exchangeService;
public ExchangeHelper()
{
//Instantiate a new ExchangeService object
exchangeService = new ExchangeService(ExchangeVersion.Exchange2010_SP2);
//Set the exchange WebService URL
exchangeService.Url = new Uri("https://hostname/EWS/Exchange.asmx");
//exchangeService.Url = new Uri("https://hostname/EWS/Exchange.asmx");
//Set the credentials of the service to the credentials
//that are associated with the impersonating account.
exchangeService.Credentials = new NetworkCredential(
"user",
"pass",
"Domain.com"
);
}
public void CreateAppointment()
{
var emailAddress = "user#doamin.com";
//Set the ImpersonatedUserId property of the ExchangeService object to identify the impersonated user (target account).
//This example uses the user's SMTP email address.
exchangeService.AutodiscoverUrl(emailAddress);
exchangeService.ImpersonatedUserId = new ImpersonatedUserId(ConnectingIdType.SmtpAddress, emailAddress);
//create a new appointment object
Appointment appointment = new Appointment(exchangeService);
//set appointment properties
appointment.Subject = "test";
appointment.Body = "testBody";
//In MSDN it says that if you dont specify the timezone, it will use the UTC timezone
//but in reality it is not working that way.
//so explicity setting the EST timezone
appointment.StartTimeZone = TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time");
appointment.Start = DateTime.Now;
appointment.EndTimeZone = TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time");
appointment.End = DateTime.Now.AddHours(1);
//add required participants
appointment.RequiredAttendees.Add(emailAddress);
newFolder.Save(WellKnownFolderName.Inbox);
appointment.Save(new FolderId(WellKnownFolderName.Drafts, "emailAddress"));
//Set it back to null so that any actions that will be taken using the exchange service
//applies to impersonating account (i.e.account used in network credentials)
exchangeService.ImpersonatedUserId = null;
return the unique identifier that is created
return appointment.Id.UniqueId;
}
The exception is "The account does not have permission to impersonate the requested user"

It's not 100% clear from your post whether the account you use for the credentials on the ExchangeService and for the ImpersonationUserId are the same. If they are, then you would not need to use impersonation and should not set that property. It seems like one should be able to impersonate oneself, but there's no need to do so, hence EWS may throw you back that exception.
If they are different, then it's pretty much as the message says: the account you use for the credentials must have the right to impersonate the user you set. This typically involves some PowerShell magic by the Exchange admin to set this up.

EWS Oauth Exception: The request failed. The remote server returned an error: (401) Unauthorized

I'm trying to create a bot that can book meetings. In order to do that i need to access the calendar of an employee to get FreeBusy info to ultimately book a meeting. I'm trying to avoid hardcoding the email and password and for that I want to use an access token from Azure AD to call EWS.
I set the properties for
public static ExchangeService service = new ExchangeService(ExchangeVersion.Exchange2013);
using this method:
public static async System.Threading.Tasks.Task UseExchangeService(IDialogContext context, string userEmailAddress, SecureString userPassword)
{
string authority = ConfigurationManager.AppSettings["authority"];
string clientID = ConfigurationManager.AppSettings["clientID"];
string resource = ConfigurationManager.AppSettings["resource"];
string appKey = ConfigurationManager.AppSettings["appkey"];
AuthenticationContext authenticationContext = new AuthenticationContext(authority, false);
ClientCredential clientCred = new ClientCredential(clientID, appKey);
AuthenticationResult authenticationResult = await authenticationContext.AcquireTokenAsync(resource, clientCred);
service.Url = new Uri(ConfigurationManager.AppSettings["serverName"] + "/ews/exchange.asmx");
service.TraceEnabled = true;
service.TraceFlags = TraceFlags.All;
service.Credentials = new OAuthCredentials(authenticationResult.AccessToken);
// USING THIS LINE IT WORKS FINE!
// service.Credentials = new NetworkCredential(userEmailAddress, userPassword); // VIRKER
}
I do get the access token from Azure AD and I have granted the permission for the application in Azure AD.
I use this method to extract the freebusytimes, it contains other more code to display the times as buttons on a herocard, but this is the call to EWS:
List<AttendeeInfo> attendees = new List<AttendeeInfo>();
attendees.Add(new AttendeeInfo()
{
SmtpAddress = "MyEMAIL",
AttendeeType = MeetingAttendeeType.Organizer
});
attendees.Add(new AttendeeInfo()
{
SmtpAddress = BookersEmail,
AttendeeType = MeetingAttendeeType.Required
});
//DateTime date1 = new DateTime(DateTime.Now.Year, DateTime.Now.Month, DateTime.Now.Day.Ad, 7, 0, 0)
// Specify options to request free/busy information and suggested meeting times.
AvailabilityOptions availabilityOptions = new AvailabilityOptions();
availabilityOptions.GoodSuggestionThreshold = 49;
availabilityOptions.MaximumNonWorkHoursSuggestionsPerDay = 0;
availabilityOptions.MaximumSuggestionsPerDay = 20;
// Note that 60 minutes is the default value for MeetingDuration, but setting it explicitly for demonstration purposes.
availabilityOptions.MeetingDuration = 60;
availabilityOptions.MinimumSuggestionQuality = SuggestionQuality.Excellent;
//TimeWindow hej = new TimeWindow();
DateTime StartDay = DateTime.Now.AddDays(1);
TimeSpan ts = new TimeSpan(9, 0, 0);
DateTime StartTime = StartDay.Date + ts;
availabilityOptions.DetailedSuggestionsWindow = new TimeWindow(StartTime, DateTime.Now.AddDays(4));
availabilityOptions.RequestedFreeBusyView = FreeBusyViewType.FreeBusy;
// Return free/busy information and a set of suggested meeting times.
// This method results in a GetUserAvailabilityRequest call to EWS.
GetUserAvailabilityResults results = service.GetUserAvailability(attendees,
availabilityOptions.DetailedSuggestionsWindow,
AvailabilityData.FreeBusyAndSuggestions,
availabilityOptions);
I have created the application in Azure AD and I have granted the following permissions:
Office 365 Exchange Online:
Use Exchange Web Services with full access to all mailboxes
Read and write calendars in all mailboxes
Read and write user and shared calendars
Access mailboxes as the signed-in user via Exchange Web Services
I've tried other answers i found on stackoverflow, however they do not do the trick for me.
Hope You can help

I am not familiar with EWS, however as far as I know that the Microsoft Graph also provide the similar feature for find the available meeting time using the rest below( refer here):
POST /me/findMeetingTimes
And if you want to using this REST for the web application so that your web app can delegate the sign-in user to perform the operation for Exchange, we can use the OAuth 2.0 code grant flow. And for how to use this flow to integrate with Microsoft Graph, you can refer the links below:
Get started with Microsoft Graph in an ASP.NET 4.6 MVC app
And here is the detail for this flow:
Authorize access to web applications using OAuth 2.0 and Azure Active Directory
Hope it is helpful.

Send different attachment to different recipient in appointment EWS (Exchange Web Service)

I am trying to send meeting invitation by Appointment class of EWS.
I have a requirement to send different attachment to different recipients. I am referencing the following links:
https://social.msdn.microsoft.com/Forums/exchange/en-US/cf4b9d9a-7bbb-4caa-9d55-300371fa84ac/ews-attachment-not-sent-with-invitation
This link is just for one or more than one attachment might to be sent but I need each recipients should have different-2 attachments.
I am trying to following in my code that might be helpful to better understand the challenge:
Appointment appointment = new Appointment(service) {
Start = DateTime.Now,
End = DateTime.Now.AddHours(2),
Subject = "XYZ Invitation",
Location = "XYZ Tower, Room No. 3",
IsAllDayEvent = false,
AllowNewTimeProposal = false,
IsResponseRequested = false,
Body = new MessageBody(BodyType.HTML, html),
ReminderMinutesBeforeStart = 60
};
int i = 0;
foreach(var attendee in attendies) { // List<string>
appointment.Attachments.AddFileAttachment(Image[i], file);
appointment.Attachments[0].IsInline = true;
appointment.Attachments[0].ContentId = Image[i];
FolderId folderCalendar = new FolderId(WellKnownFolderName.Calendar, attendee);
appointment.Save(folderCalendar, SendInvitationsMode.SendToNone);
appointment.RequiredAttendees.Add(attendee);
i++;
appointment.Update(ConflictResolutionMode.AutoResolve, SendInvitationsOrCancellationsMode.SendOnlyToAll);
}

You must use Bind method of Appointment class in order to send different attachment second time to add receipt.
appointment.Bind(ExchangeService, ItemId, PropertySet);
Binds to an existing appointment and loads the specified set of properties. Calling this method results in a call to Exchange Web Services (EWS).
I hope it helps you.

Allow impersonation using ews

I'm trying to create a program in C# which should make it able to create appointments in someone else's Outlook calendar. I have code which makes it able to create appointments in my own calendar. I searched on Google and I found I should use impersonation. So I added the line:
service.ImpersonatedUserId = new ImpersonatedUserId(ConnectingIdType.SmtpAddress, emailAddress);
This is my code:
private void button2_Click(object sender, EventArgs e) {
try{
ExchangeService service = new ExchangeService();
service.UseDefaultCredentials = true;
service.Credentials = new WebCredentials("Test#domain.com", "password");
service.AutodiscoverUrl("Test#domain.com", adAutoDiscoCallBack);
service.ImpersonatedUserId = new ImpersonatedUserId(ConnectingIdType.SmtpAddress, "Test2#domain.com");
Appointment appointment = new Appointment(service);
// Set the properties on the appointment object to create the appointment.
appointment.Subject = "Tennis lesson";
appointment.Body = "Focus on backhand this week.";
appointment.Start = DateTime.Now.AddDays(2);
appointment.End = appointment.Start.AddHours(1);
appointment.Location = "Tennis club";
appointment.ReminderDueBy = DateTime.Now;
// Save the appointment to your calendar.
appointment.Save(SendInvitationsMode.SendToNone);
// Verify that the appointment was created by using the appointment's item ID.
Item item = Item.Bind(service, appointment.Id, new PropertySet(ItemSchema.Subject));
}
}catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
internal static bool adAutoDiscoCallBack(string redirectionUrl) {
// The default for the validation callback is to reject the URL.
bool result = false;
Uri redirectionUri = new Uri(redirectionUrl);
// Validate the contents of the redirection URL. In this simple validation
// callback, the redirection URL is considered valid if it is using HTTPS
// to encrypt the authentication credentials.
if (redirectionUri.Scheme == "https") {
result = true;
}
return result;
}
The problem is that I keep getting this error ""The SMTP-address has no mailbox associated with it."
Is it because impersonation isn't allowed on the server? If so how do I allow it?
I hope someone can help.
Ps: Sorry for the bad english

A few suggestions if this is Office365 or Exchange 2013 you first need the PrimarySMTP address of the Mailbox you wish to access eg
String MailboxToAccess = "PrimarySMTP#domain.demo";
Note for some tenants the SMTP and UPN/Logon are the same but that is not always the case.
This is what user you are going to be impersonating eg
service.ImpersonatedUserId = new ImpersonatedUserId(ConnectingIdType.SmtpAddress, MailboxToAccess);
You should also add in the X-AnchorMailbox header https://learn.microsoft.com/en-us/archive/blogs/webdav_101/best-practices-ews-authentication-and-access-issues eg
service.HttpHeaders.Add("X-AnchorMailbox", MailboxToAccess);
Also when you go to save the Appointment use the FolderId class with the Mailbox overload to ensure your hitting the correct Mailbox eg
FolderId CalendarFolderId = new FolderId(WellKnownFolderName.Calendar, MailboxToAccess);
appointment.Save(CalendarFolderId,SendInvitationsMode.SendToNone);
Cheers
Glen

How to send an email in C# using a different email account than the logged in user

I have a working form which sends emails from the default logged in account. I am trying to add a feature where the user can select an email account from a drop down list and send the emails via an alt address, like info#companyname.com or support#companyname.com. I am trying to use the "SendUsingAccount" option but no luck. I have look online but mostly find examples using VB which im not familiar with. My code is as follows:
Microsoft.Office.Interop.Outlook.Application objOutlook = new Microsoft.Office.Interop.Outlook.Application();
var mic = (MailItem)(objOutlook.CreateItem(OlItemType.olMailItem));
Inspector oAddSig = null;
mic.sendusingaccount = ?????????????? //here is where i need the help
mic.Subject = "Announcing Participant Website Enhancements!";
mic.Importance = OlImportance.olImportanceHigh;
mic.BodyFormat = OlBodyFormat.olFormatHTML;
//mic.Attachments.Add(PDFAttachment + yearending.Text + ".pdf");
object emailBody = ToolBox.GetStringFromTextFile((string)EmailBody);
oAddSig = mic.GetInspector;
mic.HTMLBody = emailBody + mic.HTMLBody;
//mic.Display(true);
mic.Send();

Well I always use the SMTP client from the System.Net.Mail namespace. It has a method called 'send' that allows you to provide the address of whom the message is 'from'
Check it out:
http://msdn.microsoft.com/en-us/library/system.net.mail.smtpclient.aspx
As long as you know the address of your exchange server (which should be OK since you are trying to use outlook in your example) everything should be A-OK. Probably a bit easier than the approach above too.

if you have a dropdown you could create a string with the value of that dd and asign sendusingaccount = your string
Microsoft.Office.Interop.Outlook.Application objOutlook = new Microsoft.Office.Interop.Outlook.Application();
string email = yourdropdown.selectedvalue;
var mic = (MailItem)(objOutlook.CreateItem(OlItemType.olMailItem));
Inspector oAddSig = null;
mic.sendusingaccount = email
I hope this help you

Outlook.Account account =
Application.Session.Accounts["Hotmail"];
mic.SendUsingAccount = account;
May be You can check the different accounts at Sessions...
You can check:
MSDN