This is a known issue that will be fixed in version 12.0.3 due out in the very near future.
Since we have not issued an official release yet the following link to the webmail.zip from 12.0.3 rc8 can be used to patch on top of 12.0.2 server.
Note: Before proceeding, we recommend:
- Make a backup of your HTML folder before applying the patch in case you run into any issues.
- We do not recommend patching older server versions.