GIDS uses a system to avoid SPAM being sent into our users and also implemented technically as much as possible to avoid SPAM being sent to our domains. One of the things to avoid SPAM is that we use mail systems that do not allow open mail-relay and we use subsystems such as :

This would mean that users in the GIDS domain should not get SPAM mails such as mails with content that is not 'work' related. If you are not able to sent a mail to a user in on of our domains it could mean that this is due to the fact that your mail server is blacklisted in a database. These databases are maintained by third parties as mentioned above. To be removed from the list you should NOT contact GIDS but your local mail administrator who should check if your company is indeed blacklisted on one of the list such as orbz should take the appropriate action. Normally if you as user are not able to sent mail to GIDS you will get a messages back saying why the mail did not arrive.
It could look a bit like this :

--- Partial Session Transcript ---
  250-server.domain.com Hello [112.11.76.12], pleased to meet you
  250 ENHANCEDSTATUSCODES
  MAIL From:
  550 5.0.0 Mail from 112.11.76.12 rejected. See https://abuse.gids.nl for more info
  QUIT
--- End Transcript ---

If you are able to perform checks yourself by using Internet WEB access you could check if your own company mail-server is an open relay by visiting this relay checker. Make sure you enter the IP or Domain you are sending from. If you need more detailed info please contact your own IT department and let them know you received your mail back from GIDS due to the fact that your mail-server is in the blacklist. Your own IT department can make sure the reason why you where placed in this blacklist can be fixed and also apply at the blacklister to be removed from this list.