Don't empty your mailbox.
QUOTE
Your message cannot be delivered to the following recipients:

  Recipient address: prodigypma@ims-ms-daemon
  Original address: postmaster@uninet.net.mx
  Reason: Over quota

and:
QUOTE
Your message cannot be delivered to the following recipients:

  Recipient address: ips-adm@ims-ms-daemon
  Original address: ips-adm@uninet.net.mx
  Reason: Over quota