If you're not able to send mail there's likely no single answer we can give, you will need to...Default address not working
The default address will not work by default, you will need to disable "No local address filter"...Disk Space Quota exceeded
This means your disk space quota is full. You will need to clear up some space to get your email...Not recieving email
If you're not recieving email there's likely no single answer we can give, you will need to...