When the browsing range of linked users has changed, new users are added, or users have moved departments, those contacts will not be transferred automatically to Salesforce. Please reconnect them manually.
1. Hover over 'Admin settings', then 'Integration with Other Services'.
2. Click on 'Salesforce', then 'Edit'.
3. Double check the list of newly added users.
If you want to send untransferred data too, click on 'Send untransferred data'. If not, save.
4. Please wait for the transfer to complete.
Please note that you will not be able to reconnect until 24 hours have passed.