This is just a step toward offline support. It's not available yet, because Android comes first.

The app is ready for offline use, but I don't want to implement it without 'full text search.' I plan to use SQLite FTS5. My initial tests with search show that offline search is storage-expensive, which could be problematic for mobile devices. So, the edge cases have started to appear. But it's the most requested feature, and the most interesting/challenging to me :)

Yeah for high-end phones with lots of storage, fully offline full text search would be really nice. Often I know that some email with a substring exists and I search for it in Mail app, and it goes off to do a server search… And when you need it most, you probably have 1 bar of range, or have no cell service and no available WiFi. Example: pulling up reservation details while traveling in a foreign country.

Or even worse, sometimes I look at some email in Mail and it’s there, and then hours later, while on bad network conditions, I look at it again and see “This email has not been fetched from the server. Download?”, which then just hangs.

I have a 1TB iPhone and a 2TB iPad. My main Gmail account is not large by any means - ~50k emails and 5GB space. Even though I have all this space on my iPhone/ipad available and willing to commit a bunch of it to email with all attachments and full text index, there seems to be no way to do it.

The Gmail app has a slider for “days of mail to sync”, but the max is 90 days, and not “All time” like one would expect. Anyways, good luck with Mailtemi!