Собственно, сама строчка
string[] er=new string[2];
er[1]="Спам";
var result = ZennoPoster.MailConfirm("0", project.Variables["login"].Value, project.Variables["password"].Value, "imap.mail.ru",993, true, true, true, false, "@project.Variables["rand"].Value", @"", 0,false,er)...