If you are receiving the following error and also running CRM 4.0 Outlook plugin, then the following fix below might help you.
“Cannot add to the server Junk E-mail Lists, you are over the size allowed on the server. The Junk E-mail Filter on the server will be disabled until your Junk E-mail Lists have been reduced to the size allowed on the server.”
Usually this is because you are only allowed 1024 addresses in your Junk Email list. Well, for our user this wasn’t the case. Their mailbox, nor any of the shared mailboxes had more than 5 added to their lists. The problem was a bug between CRM 4.0 and the plugin for Outlook. In this instance it was between Outlook 2007, Exchange 2007, and CRM 4.0. To fix follow the steps below.
Right click on an email, go down to Junk and click on “Junk E-mail Options…”
Go to the “Safe Senders” tab and uncheck the two bottom options:
– Also trust e-mail from my Contacts
– Automatically add people I e-mail to the Safe Senders List
That should prevent the error message from popping up again for the user.
If you research that error, a lot of times it has to due with a bug due to the mailbox being cached with exchange. So if you aren’t running CRM 4.0 and still receiving the error above try the following: Disable Cached Exchange Mode, Delete the .OST file, and then Re-Enable Cached Exchange Mode (Source: http://social.technet.microsoft.com/Forums/en-US/exchange2010/thread/83edd4c5-88b2-4f59-9736-f580183d6af1/)