Airmail offers a great set of features, and, important for me, good integration with Gmail and a variety of other services including Google Drive, Dropbox, OneDrive, Box, Things, Google Tasks, Fantastical, Evernote, and Things. The app is remarkably customizable, both in its behaviors and in appearance. Even better, its possible to sync these customizations with the desktop version of the application, so you only have to configure the app once. The app designers also made smart choices (and allow further customizations) about which settings sync and which ones dont, which is great since I dont read email exactly the same way on my phone as on my desktop. Unfortunately, reliability issues turn what should be a five-star review into only a one-star review. Most notably, I can archive or delete several dozen messages on my phone or iPad, only to see that these actions have not been reflected on the server *and* to have them reappear in the phone a few minutes later. This makes me duplicate a lot of work, and its frustrating. So, in summary, this is a great app that has become progressively less reliable over the last year or so. Until they get their act together, I recommend you get a different app.