When running the Symantec Mail Security for Microsoft Exchange (SMSMSE) installer the following error message is shown:
Microsoft Internet Information Services is required for installing Symantec Mail Security for Microsoft Exchange.
The install does not complete.
1. Turn on detailed installer logging for SMSMSE: How to obtain detailed MSI logging while installing or uninstalling Symantec Mail Security for Microsoft Exchange (SMSMSE) version 6.5 & older.
NOTE: This step is not necessary for version 6.5.5 and higher as verbose installation logging is enabled by default.
2. In the installer log find the text fnPreCheckIISInstalled.
3. There may be an error message similar to this in the logs:
IIS is a pre-requisite for SMSMSE. The installer checks that it is present and running. If not, the installer does not complete.
Install IIS and ensure it is running. See the following article for details: What IIS Settings are Required to Install and Run Symantec Mail Security for Exchange?