Understand the original
Large color scans and photos often occupy more space than text pages. A short receipt and a long illustrated report have very different compression potential. Devices and forms may also measure megabytes differently.
Try conservative settings first
Begin with optimization and compare the result. The tool does not silently remove pages to reach a target. If necessary and acceptable, try strong compression with balanced quality, then the smaller profile.
Stop before the document becomes unreadable
Strong compression turns pages into pictures and loses selectable text, interactive features and verifiable signatures. Review names, dates, codes and stamps with zoom. If fitting 2 MB would damage readability, request an alternative or separate permitted attachments. Always retain the original.