I have a C# program that connects to my Exchange Server 2010 and is able to read every email.

I am using the microsoft.exchange.webservices.dll library.

The problem is, that this program gives back the following exception on Exchange Server 2013: "The remote server returned an error: (501) Not Implemented."

I have no idea what's the difference between these 2 servers.

Some Code Snippets:

ExchangeVersion version = ExchangeVersion.Exchange2013; ExchangeService service = new ExchangeService(version); service.Credentials = new NetworkCredential("user", "pw", "domain"); service.AutodiscoverUrl("emailaddr");

and here happens the exception:

SearchFilter sf = new SearchFilter.SearchFilterCollection(LogicalOperator.And, new SearchFilter.IsEqualTo(EmailMessageSchema.IsRead, false));

FindItemsResults<Item> findResults = service.FindItems(WellKnownFolderName.Inbox, sf, new ItemView(20));

service.LoadPropertiesForItems(findResults.Items, PropertySet.FirstClassProperties);

string mailsender = item.LastModifiedName;

• Edited by Danielb95 21 hours 55 minutes ago
• Moved by jim-xuModerator 5 hours 3 minutes ago Exchange Development

The 501 isn't an EWS error so the problem is more fundamental connection related issue, I would check the EWSURL that is coming back from Autodiscover is that URL accessible and correct (eg could be misconfigured) ? I would suggest you first test is using https://testconnectivity.microsoft.com/ . And then try EWS itself using the EWSEditor https://ewseditor.codeplex.com/ . I would also review http://www.c7solutions.com/2014/06/exchange-web-services-ews-and-501-error to see if this is applicable to you.

Cheers
Glen

It's the same problem with the EWSEditor.

It shows me all the data of the Exchange Server but when I want to open a message folder, he throws the 501 exception.