[haus]

It's not when you save anything. "Store attachments on card" means to separate the attachment files that are received in your inbox and put them on the storage card, where they are accessed by tmail while it is running. That's separate from holding down on an attachment and doing a "Save As", which pulls the attachment out of the Pocket Outlook mailbox and saves it as an independent file.

I wonder if the attachment folder was empty because there was an SD problem, do you have no attachments (different from embedded items, possibly), or was it after you unchecked the box (PO would have moved them to internal storage by then).

Anyway, try it with attachments off the card, maybe soft reset for good measure, and let me know if it continues to crash. Again, I've had no problems with an Exchange account and 2 IMAP boxes with maybe 250 messages each inside, all saved on internal storage.

I almost never send SMS messages, though, but I do receive quite a few (server status, etc.)