Occasionally, maybe once a year, Gmail sends a security recommendation to turn off "legacy app access" (or whatever it's called). I think, sure, I can enable it next time I do an offline IMAP/POP backup. So I disable it.
An hour or two later I get a security alert. A failed attempt to access my email! They knew my password, but the access was blocked by Gmail. I should change my password. Every time I fall for it, and it takes me a while to recall what it is. I have two Gmail accounts. One downloads from the other using POP/IMAP. This requires "legacy app access" for some reason. And when that's disabled, Gmail blocks itself. The strange thing is, it never recognizes that the access attempt is from a Google/Gmail server IP address.
PS: I don't want to forward. It adds headers.