PST Mail has instantly become one of the most important app on my iPhone. When my iPhone 6 mysteriously dumped 4 years of emails and left me with only empty folders, I discovered that iTunes does not backup email! Since I have all of my email in Outlook on my desktop computer, I needed a way to put my emails back on my iPhone. That’s when I discovered PST Mail. In just a few minutes I was able transfer 9 GB of PST files to my iPhone - 146,561 emails in dozens of folders going back to 2001. Now instead of just the four years of emails received on my phone, I have almost two decades of history, with each PST’s folder structure intact. The search functions are excellent, allowing you to also search subfolders of a PST or all PSTs at once. Although the program does not send or receive email, you can forward or reply to emails within the app and they are queued up in the standard iPhone mail app.