Search attachments from a mailbox using EWS Managed API and C#

Question

I want to search all attachments from a mailbox having certain keywords in their name.I am doing this using C# EWS Managed API(version 2.2). I am able to access the Item with attachments using Item.HasAttachment:true property and the code is working as expected. But the processing time is very long.

The current process flow is : 1.Get all the folders from a mailbox. 2.For each folder, search items having attchments (using Item.HasAttachment:true searcFilter). 3.Check whether the Attachment name contains the keywords.

I need to know if there is a better and faster way to access attachments in a mailbox/folder using EWS. Instead of checking every mail item, is there a way to apply filter for attachments on folder level?

Below is the code snippet used to fetch the attachemnts by name keyword

SearchFilter searchFilter = new SearchFilter.IsEqualTo(ItemSchema.HasAttachments, true);        //SearchFilter for finding item with attachments
        FindItemsResults<Item> searchResults = null;
        FileAttachment fileAttachmentobj = null;
        ItemAttachment itemAttachmentobj = null;

        for (var j = 0; j < folder.Count; j++)      //Looping for all the folders in a mailbox
        {
            for (int i = 0; i < strAttachNameKeyword.Length; i++)       //Looping for keywords to be searched
            {
                searchResults = service.FindItems(folder[j].Id, searchFilter, view);
                if (searchResults.TotalCount > 0)
                {
                    service.LoadPropertiesForItems(searchResults, new PropertySet(BasePropertySet.IdOnly, ItemSchema.HasAttachments));
                    foreach (Item item in searchResults)    //Processing each item in  SearchResults
                    {
                        item.Load();
                        foreach (Attachment attachmentObj in item.Attachments)  //for each attachment in an item
                        {
                            //attachmentObj.Load();
                             fileAttachmentobj = attachmentObj as FileAttachment;
                             itemAttachmentobj = attachmentObj as ItemAttachment;
                             if (fileAttachmentobj != null && (fileAttachmentobj.Name.Contains(strAttachNameKeyword[i])))
                             {
                                //fileAttachmentobj.Load();
                                Console.WriteLine(fileAttachmentobj.Name);
                                Console.WriteLine(fileAttachmentobj.Size);
                                Console.WriteLine(fileAttachmentobj.Id);
                             }
                        }
                    }
                }
            }                       
         }

Answer 1

I'd suggest you use a QueryString instead of a SearchFilter which means you'll be doing a Content Index search rather the a folder restriction which is much faster. eg

FindItemsResults fiItems = service.FindItems(QueryFolder, "Attachment:blah.pdf", iv);

You can easily test this using the EWSEditor https://github.com/dseph/EwsEditor/releases if you right click a folder->search for items and select the AQS radio button it has a simple interface for AQS/KQL queries