Message posting normally occurs at the tail end of a rule's execution – a sort of “final action” even though not technically an action like expressions in Action rows.

An exception to this behavior occurs for Column 0. A rule statement with Ref = 0 posts at the beginning of Rulesheet execution. If you want to force your rule statements in Column 0 to post after the Action rows execute, use Ref values of A0, B0, and so on (rather than 0.)