"Respond with" field is grayed out when trying to set up automatic response for Media Remove alerts so it appears that the alerts can not be configured.
In Backup Exec 2012 the Media Remove option cannot be configured from the Backup Exec Menu | Configuration and Settings | Alert Categories because it is set to "Cancel" and grayed out.
Same problem is visible in older BE versions too. Under "Configure Alert Categories" window, the Media Remove category response option grayed out
To configure the automated Respond with for these alerts, follow the steps given below:
1. Browse to X:\Program files\Symantec\Backup Exec (X: being the driver letter where Backup Exec is installed)
2. Run BEUtility.exe
3. Add the media server from File | New | New Media Server
4. In BEUtility, select the All Media Servers, select the Media Server Name
5. From the left pane under Service Tasks click Edit configuration (or right click on media server name and select Edit Configuration)
6. Under Automated alert responses configure the Media Remove Alert with the required alerts response.