How does iOS Mail suggest folders for archival?

I file my mail meticulously. The only things I want in my inbox is stuff I need on hand quick (like a boarding pass) or stuff that still needs immediate action. Everything else I try to file in a myriad of folders spread over various IMAP accounts and even some local folders. On macOS Mail I usually just end up dragging emails to one of the folders in my always displayed folder list (left pane). On iOS Mail I usually hit the folder icon at the bottom. Two things can then happen (and I’m not clear as to why one or the other happens): I’m displayed a list of folders to chose from, or I am presented a box with two options: a specific folder to move it to and “Other Mailbox…”.

It’s that specific folder I can’t figure out. Sometimes it’s an excellent suggestion, but other times it’s terribly off. But I cannot figure out what the logic behind this suggestion is. Is it sender, is it subject, is it related to email content? So far, every time I thought I had figured it out I eventually get shown a suggestion that appears to defy the logic I thought applied.

Does anybody understand how this really works?

I can’t tell you how it works, but I can tell you that when it happens to me, it seems to be based on the sender. I have a folder called “Actions” where I temporarily store messages that need to be acted upon in some way. Nothing stays in there for more than a week, and there’s rarely more than 5 or 6 messages in there at any given time. Any time a message from my wife is in there, all messages from my wife generate that two-option dialog, with that Action folder as the recommended destination. If I take my wife’s message out of that folder, I stop getting the dialog.

I always have thousands of messages from her in my Archive folder, but I don’t ever get that two-option dialog with the Archive folder as a suggestion. Maybe the Archive folder is exempt from whatever generates that dialog. I don’t know.

Thanks, Anthony. For a while I thought it was sender-based too, but then it appeared to switch to suggesting other folders for certain people. I’l keep an eye on that.