Emailing them to yourself (instead of just leaving them in your phone's camera roll) gives you a timestamp that's harder to dispute than just a photo's metadata, and it means you still have them even if you lose your phone or switch devices before your deposit gets sorted out.
@ pertamina.....gas isi 12 kg, ini saya cek..yg pertama tabung isi berat 26.6kg, ya kedua tabung kosong beratnya 16,17kg, jadi isinya hanya 10,43 kg saja, bayar 12 kg...kemana ya 1,57 kgnya? Ini baru 1 tabung, sedangkan penjualan 1 hari bisa ribuan tabung