Ask HN: What do I tell my clients about email images being switched off?

It's Friday morning, and again I seem to be having the perennial client hand wringing discussion ritual because people can't see the client's lovely email images because they have images switched off in their email client.

It doesn't matter how many times I tell the client to just send nicely written plain text emails. Clients love seeing their logos and products in massive size and multicolour.

There seem to be no stats which can reassure clients, most studies seem to suggest roughly 50% of people don't see images. A stat I will avoid burdening clients with as it will only worsen their marketing paranoia.

So, HN, is there any argument or reasoning I can use to convince clients that they should just get over this compulsion to shove images down people's virtual throats?

Or at least a way to end these discussions as soon as possible so I'm not wasting time babysitting corporate egos.