如何编写邮件主题和标题

string mailBody = string.Format("<h2>取回密码短信</h2><br>以下是您的登录密码:{0},请妥善保管。<br>", pwd);

string
smtpName = ConfigurationManager.AppSettings["SendEmailName"],
smtpPwd = ConfigurationManager.AppSettings["SendEmailPWD"];

if (smtpName.IsNullOrEmpty())
smtpName = "[e-mail]";

if (smtpPwd.IsNullOrEmpty() || smtpName == [e-mail])
smtpPwd = "123456789";

//发送邮件
new ByecityMailSmtp("mail.byecity.com", 25, smtpName, smtpPwd, "202.106.0.20", false, "-会员服务", smtpName).Send(
smtpName,
email,
"会员服务丨会员取回密码确认邮件",
mailBody,
new string[] { },
Encoding.Default,
true,
MailPriority.Normal);