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 Tuesday, May 26, 2015 9:34 AM
• Moved by jim-xuModerator Wednesday, May 27, 2015 2:26 AM Exchange Development

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.

Edit: I just noticed, that I can enter the inbox with EWSEditor, it actually shows me the inbox, but the error 501 is still coming.

Edit2: Just tried to create mails in the draft folder. It works. How can this be possible? I can create mails on the server, but I can't read the inbox? (Still get the error though) 

• Edited by Danielb95 Wednesday, May 27, 2015 8:02 AM

Tried the instructions of your link. Didn't change anything.

How could i detect the program, that's affecting my Driver?

Or is there a possibility to edit my code so, that it decrypts the HTTPS traffic itself?

• Edited by Danielb95 Thursday, May 28, 2015 11:35 AM

Finally found the problem:

There was a load balancer between exchange server and my server. I'm bridging this load balancer now -> Works perfectly

• Marked as answer by Danielb95 19 hours 55 minutes ago