Meta Search - Search your Desktop, Google Drive, Dropbox, Gmail, Evernote.
Google Groups - Google Groups allows you to create and participate in online forums and email-based groups with a rich experience for community conversations.
Vaultedge - Access all your documents in one place.
Groups.io - Email and web based discussion group software, includes archiving, emails, wiki, polls, file...
Google Cloud Search - Search across all your company's content in G Suite.
Gaggle Mail - Gaggle Mail is a simple and easy to use email list manager.