> file access times will only be updated if they are newer than the creation or modification times.
relatime ensures the atime is updated only if it is *older* than the creation or modification time. If it's already newer, it's a good bet that mutt & archaic friends will do the right thing.
I'm bummed to even see relatime. Why don't the kernel guys deprecate atime for a year or two, then purge it entirely and with prejudice? It seems easier to fix the few misguided apps that still use it than to pussyfoot around it for the next 20 years.
But I've never seen a situation where atime was necessary... Are there apps other than mutt that I just don't know about?