Describe the bug

config/cache.go:151-153:

func normalizeContactEmail(email string) string {
    return strings.ToLower(strings.Trim(strings.TrimSpace(email), ","))
}

Email addresses passed in from From: headers commonly arrive as <[email protected]>. The angle brackets are not stripped, so the cached entry stores <[email protected]> literally and never matches future lookups against [email protected].

Expected behavior

Strip < and > (and any leading/trailing whitespace) before lowercasing.