Communication is all about achieving clarity and alignment. One of the biggest learnings I have had over the years is that most people treat communication like a scarce resource that is doled out sparingly. Part of this is conflict avoidance, part of this is organizational hierarchical thinking and part of this is just poor communication skills.
My experience is that the opposite is true. If you haven't communicated your point clearly, with specificity AND with validation on what the other side has heard, and what the plan of record and going forward actions are, then you haven't communicated effectively.
This may take ten times to get the message across, and multiple back and forths to ensure clarity and alignment on the takeaways.
Bottom Line: Repetition is a FEATURE, and not a BUG of communication.