Sending Mails in group

Check this link

How to send attachment and group mail in ASP.NET[^]

If you actually mean that you want to send an email toa group of people, all you have to do is add the appropriate number of email addresses to the To property (keeping in mind that all of the recipients will see all of the other recipients' email addresses):

System.Net.Mail.MailMessage message = new System.Net.Mail.MailMessage();
message.To.Add("person1@whocares.com");
message.To.Add("person2@whocares.com");
message.To.Add("person3@whocares.com");

If you want to send more than one email to a single person, you can either merge the bodies of the emails, or send an indvidual email for each "body" that you have.

try this code

public static void SendMail(string Subject, string Body, bool IsHtml, string From, string To, string Cc, string Bcc)
{
    const char SEPARATOR = ',';
    string[] Tos = new string[0];
    string[] Ccs = new string[0];
    string[] Bccs = new string[0];

    MailMessage mailMessage = new MailMessage();
    mailMessage.From = new MailAddress(From);
    mailMessage.Subject = Subject;
    mailMessage.Body = Body;
    mailMessage.IsBodyHtml = IsHtml;
    if (!String.IsNullOrEmpty(To))
         Tos = To.Split(new char[] { SEPARATOR }, StringSplitOptions.RemoveEmptyEntries);
    if (!String.IsNullOrEmpty(Cc))
         Ccs = Cc.Split(new char[] { SEPARATOR }, StringSplitOptions.RemoveEmptyEntries);
    if (!string.IsNullOrEmpty(Bcc))
        Bccs = Bcc.Split(new char[] { SEPARATOR }, StringSplitOptions.RemoveEmptyEntries);
    foreach (var item in Tos)
    {
        mailMessage.To.Add(new MailAddress(item));
    }
    foreach (string item in Ccs)
    {
        if (!isMailCointained(item, Tos))
        {
            mailMessage.CC.Add(new MailAddress(item));
        }   
    }
    foreach (string item in Bccs)
    {
        if (!isMailCointained(item, Tos) && !isMailCointained(item ,Ccs))
        {
            mailMessage.Bcc.Add(new MailAddress(item));
        }
    }
    try
    {
        SmtpClient smtpClient = new SmtpClient();
        // add your smtp server!
        smtpClient.Host = ConfigurationManager.AppSettings["YOUR EMAIL SERVER"];
        smtpClient.Send(mailMessage); 
 }
     catch(Exception exc){// add your exception handlers.. }
}
private static bool isMailCointained(string mail, string[] mails)
{
    bool toRet = false;
    foreach (var item in mails)
    {
        if (mail == item)
            return true;
    }
    return toRet;
}

If you call the SendMail method using:

SendMail("Hello", "<h3>Hello from myrocode!</h3>", true,
               "myEmail@a.com", "a@a.com,b@a.com,c@a.com", "z@a.com,b@a.com", "x@a.com,y@a.com,z@a.com");

You email will be deliverd with the following headers:
To: a@a.com
b@a.com
c@a.com
Cc:z@a.com
Bcc:x@a.com
y@a.com

Hi,

if you add each recipient in BCC(Blank carbon copy) then mail will be send as individual.

thanks
-amit.

This article-[Sending Email in C# (Sync/Async, Multiple recipients, Attachments, etc)][^] might help you.