Send NewsLetters But Not Receive and Queud emails

[tanzeelniazi]

2 days ago i send a emails
I am using vbmail pro and i send email to all members include my user also i check my email not receive emails i dont know why
after i am login ACP i see number of queued emails 17000+ and yesterday is 18000
why i and other members not receive emails and why working number of queued emails slowly how working fast this

4 days i ago i test vbmail and i select only admins after i send email i receive but when i select all usergroups email not receive
Total members i have 20,000.

Vbmail bounced setting is Off because i dont know how to set ? its necessary or not ? whats is the functions