A more professional way to ensure the recipient can open the file with all its assets is to "Package" the document: Go to .

Ensure all images are linked properly. Sometimes, the pathing for high-resolution links can break during the IDML conversion. Quick Comparison: INDD vs. IDML INDD (Standard) IDML (Exchange) Compatibility Specific version only Multi-version compatible File Size Larger (contains previews) Smaller (XML-based) Stability Often used to "clean" buggy files Usage Active design work Archiving and down-saving