What is your question?
If you are asking whether these portals allow viewing correspondence, in my experience of at least three different portals , the answer is no. Remember that correspondence these days can normal snail mail or email. It’s difficult, because of the number of different emails packages, to provide integration into the portals.
Depending on the portal, there may be various documents on the portal. Ie strata plan, drainage diagram, work orders, financials etc
The documents available on a portal depends on what portal your SM is using.