<DKIM> maxage causes loss of local email

[Janna Martl]

On Wed, Mar 11, 2015 at 01:50:13AM -0400, Janna Martl wrote:
>OK, so I think I'm understanding this UID check idea: we have two
>timezones going on; e.g. the top one represents the local messagelist,
>containing X, Y, and W, measured in UTC, and the bottom one represents
>the remote messagelist, containing X, Z, and W, measured in UTC -0900
>(so "0" in the bottom timeline means "00:00 -0900" = "09:00 +0000").
>
>                X  Y      W
>|--------------|---------------|
>-24             0             24
>
>                   Y  Z   W
>        |--------------|---------------|
>       -24             0             24
>
>If we don't try to correct for timezones, each messagelist will
>contain things > 0 (with respect to its native timezone), so
>messagelist1 = [X,Y,W] and messagelist2 = [W]. This is bad because Y
>will get deleted from messagelist1. However, this is the only thing
>that can go wrong. Create a (maxage + 1) messagelist for the bottom
>that contains time > -24, and delete anything from messagelist1 that
>is on this expanded list but not in messagelist2. Do the same in the
>opposite direction, because we don't know a priori which direction the
>shift is in. I really like this -- it's so much less messy than what I
>was trying to do.

The downside, though, is that asking both for messages within maxage
and messages within (maxage + 1) means that you're doing two
searches instead of (previously) one; if this is done for both local
and remote, you're doing two IMAP search queries, and that takes
nontrivial time.