According to this morning's issue of AdBumb
, AOL version 7.0 has a default setting that automatically blocks all HTML email. AOL purportedly claims this saves users from any potentially "dangerous" HTML email. Others claim this mostly saves AOL server space (and I must say this sounds like reality to me). In the past AOL older versions didn't allow full HTML email through anyway, so email marketers had to send stripped down versions of their campaigns to the list. The newer v. 7.0 was supposed to solve this, but unless millions of users change their default settings (ha) it won't.
Personally I'm wondering if Yahoo and Hotmail free email versions are going to be far behind. Right now Hotmail's been coping with HTML influx by making free mailboxes smaller, so if folks don't clean them out frequently, email bounces.