Actually, experience shows the opposite to usually be the case.
If you try and engage people on how and why, it almost always escalates in some way.
I think I understand what you mean. However, there is a distinction between "send notification of deletion" and "give room for debate and escalation".
I don't know if the forum software allows this but what usually "works" is:
- moderator presses delete button
- gets page/popup/whatever with a text field for "reason for deletion".
- post gets deleted (or moved to "safe" area, whatever's your thing)
- poster of the offending gets A PM along the lines of
"your post such and such has been removed. reason given was <whats-in-the-text-field>. This message is intended purely as notification. ... some other stock message you think fits your forum".The idea here being that the moderation action of "delete post" should be simple for the moderator. And notification of the user should be automatic, not extra work. That is, should you choose to have that as feature.
Main thing I am getting at that notification of the user should result in less grievances, not more. Just make sure that the stock message you plonk in there makes it clear this notification is a notification, not an invitation for debate of the moderation decision.
Anyways, the forum seems to work fairly well on the whole, so keep it up.