I' m Ilker. I 'm from Tukey.We are use Proofpoint .We are problem recivie one mail addrees.Error "reject=550 5.7.1"
Hello ilker,Please open a ticket on:http://www.f-secure.com/en/web/business_global/support/contact/requestIn the description field, please provide the activation ID of the Message Security Gateway you're using.This can be found under "System"-->"licenses and updates"-->"license" tabAlso, please provide us with the IP address of the box.Thanks in advance.
This usually is a problem when sending mails. Thanks for the support link.