在我的例子中,我只会发送excel文件,这就是内容类型设置的原因.显然,这可以更改为支持任何类型的文件附件.

作为参考,变量esb是ExchangeServiceBinding类型的类级变量.

编辑

我还应该注意,在这个例子中,我没有检查交换操作中的响应类型是否成功.如果您想知道您对EWS的呼叫是否真的有效,那么一定要检查这一点.

public void SendEmail(string from,string to,string subject,string body,byte[] attachmentAsBytes,string attachmentName)
        {
            //Create an email message and initialize it with the from address,to address,subject and the body of the email.
            MessageType email = new MessageType();

            email.ToRecipients = new EmailAddressType[1];
            email.ToRecipients[0] = new EmailAddressType();
            email.ToRecipients[0].EmailAddress = to;

            email.From = new SingleRecipientType();
            email.From.Item = new EmailAddressType();
            email.From.Item.EmailAddress = from;

            email.Subject = subject;

            email.Body = new BodyType();
            email.Body.BodyType1 = BodyTypeType.Text;
            email.Body.Value = body;

            //Save the created email to the drafts folder so that we can attach a file to it.
            CreateItemType emailToSave = new CreateItemType();
            emailToSave.Items = new NonEmptyArrayOfAllItemsType();
            emailToSave.Items.Items = new ItemType[1];
            emailToSave.Items.Items[0] = email;
            emailToSave.MessageDisposition = MessageDispositionType.SaveOnly;
            emailToSave.MessageDispositionSpecified = true;

            CreateItemResponseType response = esb.CreateItem(emailToSave);
            ResponseMessageType[] rmta = response.ResponseMessages.Items;
            ItemInfoResponseMessageType emailResponseMessage = (ItemInfoResponseMessageType)rmta[0];

            //Create the file attachment.
            FileAttachmentType fileAttachment = new FileAttachmentType();
            fileAttachment.Content = attachmentAsBytes;
            fileAttachment.Name = attachmentName;
            fileAttachment.ContentType = "application/ms-excel";

            CreateAttachmentType attachmentRequest = new CreateAttachmentType();
            attachmentRequest.Attachments = new AttachmentType[1];
            attachmentRequest.Attachments[0] = fileAttachment;
            attachmentRequest.ParentItemId = emailResponseMessage.Items.Items[0].ItemId;

            //Attach the file to the message.
            CreateAttachmentResponseType attachmentResponse = (CreateAttachmentResponseType)esb.CreateAttachment(attachmentRequest);
            AttachmentInfoResponseMessageType attachmentResponseMessage = (AttachmentInfoResponseMessageType)attachmentResponse.ResponseMessages.Items[0];

            //Create a new item id type using the change key and item id of the email message so that we know what email to send.
            ItemIdType attachmentItemId = new ItemIdType();
            attachmentItemId.ChangeKey = attachmentResponseMessage.Attachments[0].AttachmentId.RootItemChangeKey;
            attachmentItemId.Id = attachmentResponseMessage.Attachments[0].AttachmentId.RootItemId;

            //Send the email.
            SendItemType si = new SendItemType();
            si.ItemIds = new BaseItemIdType[1];
            si.SavedItemFolderId = new TargetFolderIdType();
            si.ItemIds[0] = attachmentItemId;
            DistinguishedFolderIdType siSentItemsFolder = new DistinguishedFolderIdType();
            siSentItemsFolder.Id = DistinguishedFolderIdNameType.sentitems;
            si.SavedItemFolderId.Item = siSentItemsFolder;
            si.SaveItemToFolder = true;

            SendItemResponseType siSendItemResponse = esb.SendItem(si);
        }