You're correct, it's an IE (go figure!) issue. Works fine in FF.
I did notice, without having any other images in my test email, that the tracking (transparent) image comes over as a broken image. Normally I'm prompted in Outlook to download images and that would account for that...but not in this instance.
Would love a double optin feature in next release. Also, what if end user does not accept HTML email? Do they get a decent text version of same?
Keep up the great work! I have tried numerous newsletter plugins and most are far too complex or just don't plain work. This one seems to be a keeper!