sendig mail to multiple recipients with html Mailto: not working c#

Question

I want to send with 1 HTML link a mail to multiple (300) recievers...

This link doesn't work. It do nothing when i press the link. mailto:person1@domain.com;person2@domain.com.......' Is there a maximum length on mailto: attribute ?

var employees = db.Employees;
            List<string> Emaillist = new List<string>();
            string email="";
            foreach (var item in employees)
            {
                if (string.IsNullOrEmpty(itemEmail) == false)
                    {
                    Emaillist.Add(item.Email.ToString());
                   

                }
                
               
            }
         
            foreach (var item in Emaillist)
            {

                email = email + item+";";

              
            }
        
            var outlookmail = "mailto:"+ email;
            return outlookmail;