In Mail 6.8, 10.8.5

For the past few days, I have received several emails, that when accessed, have a banner at the top of the email saying that the email contains images and that should I wish to view the images, I must click "here".

The place where the images would otherwise be is occupied by a small blue icon.

When I click as directed, the email and all associated images (re)opens normally.

Is this situation a result of an Apple security initiative or did I mess up some setting? And if so, what's the fix?

I don't think it is an Apple initiative because I am not seeing it in Mail 6.8 (OS X 10.8.5) nor am I seeing it in iOS 7 Mail. Rather, I think if you will view the initial message and banner in raw source you will find JavaScript (not Java) that drives the loading of the full message text. Some senders of large messages are using this technique because so much email is being opened on smart phones with small screens, limited memory, and pernicious data plans. Basically it is a variation on "…if you are having trouble viewing this message click here". This would also be a good way to get around spam filters by substituting large image files for scannable text and it could even be used as a vehicle to distribute malware.

The fix is to ask to be removed from the mailing list or flagging the messages as Junk mail. If you have the Developer's menu installed in Mail disable Javascript (I'm not sure what would happen if you do that, but it would be interesting to find out).

JoeMike-

Me thinks you got it, to wit, I recently installed SpamSeive.

I think (retrospectively) that in addition to what I described, the email was also identified as (suspected) spam by SpamSeive. Ergo, the (hidden) images were not presented.

In the next few days and after more mail has arrived, the truth will out (or so I hope).

Thanks for clearing some of the cerebral detritus.

It sounds like your Mail -> Preferences -> Viewing tab's Display remote images in HTML messages checkbox may have become unchecked. I have mine unchecked, and what you describe is exactly what any message containing remote images looks like when I open it. (To be precise, there's a blue bar across the top of the message, with This message contains unloaded images at the left and a Load Images button at the right.)

Do you mean Safari's Developer menu? I'm not aware of any such animal for Mail.app.

Overnight, I received 2 emails SpamSeive identified as probable spam, and as before, I had to click in order to see the images.

It's still early, but it's beginning to look like the issue I first noted is a consequence SpamSeive doing its thing.

I checked my Mail Preferences and indeed the "Display remote images in HTML messages" is enabled. Still, I toggled the setting, just in case…

FWIW, SpamSeive seems to be a fine application with first-rate tech support, but the suggested training program (that I am doing) is a bit of a chore.

Oops - my bad!

I am now 98.52% certain that the click to open images was in fact a consequence of SpamSeive. The only instance since my first post was a SpamSeive false positive. All other incoming email works as divined.