I understand. The way I've taken to structure my messages is to provide the terse summary up front then elaborate as I go, summarize tersely at the end and re-pose any pressing questions. This way the reader can mostly skip the middle of my email and go from the executive summary at the top and forward themselves to the last few sentences and hit reply. If they want more detail, it's all there.

I try to keep away from any overly technical jargon, and kind of "dumb it down" aka, use non-technical language as much as I can while still keeping to the point and being accurate. If they want the technical jargon version, they can ask, but they never do.

I find it helps me since I can go back and reference the information if I need it, or point the client to it and go over it with them later if they ask at a later date.

I don't know if that's something that's possible with your work, but it seems to minimize the follow ups and the end user seems to be happy most of the time. There's always a few that will complain, but I've gotten more compliments on my communication style than anything.