I had one NSF file with around 260 contacts, and manual methods didnt work at all. What annoyed me was how every approach worked partially but created new issues. I tried converting in smaller batches, thinking it might help. It didnt. Some contacts came out fine, others didnt. That inconsistency made everything worse. The worst part was duplicate entries and missing phone numbers showing up randomly. After wasting time testing different methods, thats when I realized bulk conversion needs a proper tool. I switched to GainTools NSF to VCF Converter and processed the whole file in one go. It kept everything aligned and didnt create duplicates. That finally felt like a real bulk solution instead of a workaround.