c# 4.0 - Maximum no. of concurrent connections exceeded for SmtpClient -

i have scenario, msmq queuing system...records queued on timely basis...a wcf listener listens queue, starts processing records records queued up...does process , sends email after that(there 10 queues , 10 listeners out of 3 listeners responsible email sending). problem facing email sending part, larger data queued records following error

service not available, closing transmission channel. server response was:       4.3.2 maximum number of concurrent connections has exceeded limit, closing transmission channel 

the class sends email is

public class {     //method static common method used other processes running in parallel     public static void sendmail()     {         mailmessage mail = new mailmessage();         smtpclient client = new smtpclient();         ///email information goes here         client.send(mail);     } } 

i guess method static smtp object instantiated each time causes problem. if increase concurrent connections not solving problem. have couple of workaround required more light on this.

1. limit no. of concurrent connections let 100. have 1000 records queued , listeners starts processing them in parallel smtp process not use more 100 connections @ time, wait complete , take next 100 , on. not sure how this.
2. use parallel foreach loop or smtpclient.sendasync method, here proficiency level not regarding these methods, little bit afraid(i need make sure there no major performance hit). needed stable , better approach solve this.