How long should I wait after filing a 90-day report by post before I should be worried?

The user is concerned about not receiving confirmation for their 90-day report submitted by post to the Chaengwattana immigration office a month ago. They are seeking advice on how long to wait before worrying and whether the online system reflects updates for postal submissions. Responses indicate that a late report incurs a 2000B fine, regardless of how late it is, and suggest confirming the submission by email if a self-addressed stamped envelope was included.