C#发送邮件附件

public string SendOutEmail(string fileName, string name, string eamil, string title, string content, string category, int OfferId)
{

//获取时间

var thisDate = DateTime.Now;
var year = thisDate.ToString("yyyy");
var month = thisDate.ToString("MM");
var day = thisDate.ToString("dd");
// 文件名
var thisName = Guid.NewGuid();
//组合文件路径
var xunilujing = "/UploadFile/" + year + "/" + month + "/" + day;
var path = HttpContext.Current.Server.MapPath("~" + xunilujing);
// 获取订单信息
var obj = new OfferInfoController().GetInfo("", out _, OfferId); //获取 obj下的name
// 获取最新的订单数据
var monitoring = new OfferMonitoringEntryController().GetListByOfferIdMaxMonitoring("", out _, OfferId);
var orgList = monitoring.Where(it => it.EntryCode == "enyUpload").ToList();
var org = orgList[0].EntryValue;
var OldPath = org.ToString().Substring(org.LastIndexOf("/") + 1);
var NewPath = path + "\\" + OldPath;
var str = NewPath.Substring(0, NewPath.LastIndexOf("\\"));
var OssUrl = OssController.UploadToOss("", out fileName, NewPath, OldPath);
SmtpClient client = new SmtpClient(SiteSetting.MailServer);
client.EnableSsl = true;
client.UseDefaultCredentials = false;
client.Credentials = new System.Net.NetworkCredential(SiteSetting.MailAccount, SiteSetting.MailPassword);
UserInfoController userContro = new UserInfoController();

var cmObj = userContro.GetInfo("", out _, obj.CMUserId, "", isAddLog: false);

var bsObj = userContro.GetInfo("", out _, obj.BSUserId, "", isAddLog: false);
MailAddress from = new MailAddress(SiteSetting.MailAccount, name, Encoding.UTF8);//初始化发件人
var deadlineObj = monitoring.Find(m => m.EntryCode == "enyCMexpectationDate");
string deadline = deadlineObj != null ? deadlineObj.EntryValue : "";
MailAddress to = new MailAddress(bsObj.UserEmail, "", Encoding.UTF8);//初始化收件人
var enyCompany = monitoring.Where(it => it.EntryCode == "enyCompany").ToList();
var enyCompanys = enyCompany[0].EntryValue;
var enyProductName = monitoring.Where(it => it.EntryCode == "enyProductName").ToList();
var enyProductNames = enyProductName[0].EntryValue;
var enyVNB_1 = monitoring.Where(it => it.EntryCode == "enyVNB_1").ToList();
var enyVNB_1s = enyVNB_1[0].EntryValue;
string EmailHtmls = "";
string mailBody = "<table>";
mailBody += "<tr>";
mailBody += "<td>We have provided the non-binding terms sheet to Client.";
mailBody += "</td>";
mailBody += "<tr>";
mailBody += "<td>Company:";
mailBody += enyCompanys;
mailBody += "</td>";
mailBody += "</tr>";
mailBody += "<tr>";
mailBody += "<td>ProductName:";
mailBody += obj.ProductName;
mailBody += "</td>";
mailBody += "</tr>";
mailBody += "<br/>";
mailBody += "<br/>";
mailBody += "<br/>";
mailBody += "<tr>";
mailBody += "<td>Regards,";
mailBody += cmObj.UserCode;
mailBody += "</td>";
mailBody += "</tr>";
mailBody += "<br/>";
mailBody += "</table>";
EmailHtmls = mailBody;

//设置邮件内容
MailMessage message = new MailMessage(from, to);
message.Body = EmailHtmls;
message.BodyEncoding = Encoding.UTF8;
message.Subject = title.Trim();
message.SubjectEncoding = Encoding.UTF8;
message.IsBodyHtml = true;

if (!string.IsNullOrEmpty(NewPath))
{
//附件
Attachment myAttachment = new System.Net.Mail.Attachment(NewPath, MediaTypeNames.Application.Octet);

//MIME协议下的一个对象，用以设置附件的创建时间，修改时间以及读取时间
ContentDisposition disposition = myAttachment.ContentDisposition;
disposition.CreationDate = File.GetCreationTime(NewPath);
disposition.ModificationDate = File.GetLastWriteTime(NewPath);
disposition.ReadDate = File.GetLastAccessTime(NewPath);

//用smtpclient对象里attachments属性，添加上面设置好的myattachment
message.Attachments.Add(myAttachment);
}

try
{
client.Send(message);
return "邮件发送成功！";
}
catch (Exception ex)
{
Log.Error(MethodBase.GetCurrentMethod(), ex);
return "邮件发送失败！" + ex.Message;
}
}