@daq,

What client are you using anyway? Perhaps it has an option to sort based on receival date, which would at least alleviate the problem. Otherwise you might want to think about replacing it with something more standard (this is independent of SMTP, the relevant standard here is the message format, RFC2822).

Anyway, I don't have an N9 so I cannot help much on that side. You might want to try setting/unsetting the automatic time update and/or changing (temporarily) your timezone/regional settings and see if that has any effect.