Yes, like PurgeandFire111 said, you have to compress the imports in your map to get the file size down.
A map optimizer usually decreases the file size of a map by deleting unneccicary and/or redundant code. It will not decrease the size of the imports of the map. Since your map is only roughly 20-400KB in size without imports (depending on map size and amount of triggers), an optimizer will only decrease the file size of that code.
To greatly decrease the size of the map, use compression methods on those large imported files such as models, textures and music.