If instant messaging icons do not display in IBM® iNotes® mail and the contact list, you look for causes.
Check the following:
The instant messaging integration features rely on the ability of the browser to directly communicate with the Sametime server. This means that the fully-qualified Internet hostname of the Sametime server must be resolvable from the browser, for example, the fully qualified Internet hostname for an IBM Domino® server named IM/Renovations might be im.renovations.com.
Therefore, either DNS must be able to resolve this address or it must be resolved to the proper IP address by some other mechanism, such as editing the local operating system's hosts file.