Today I got a question by phone of one this blog-followers (hi Erwin!). His question was if attachments on SharePoint list items are searchable. I had to confess that I've never had this question before. A first quick search on the internet gave the answer: no!
But, that isn't the truth. I just search a bit around, because I was curious if that was really true. I found that list attachments are indexed in SharePoint search. And because of that, searchable!
The trick, or if you like the problem, is the presentation of the results by SharePoint. The results are not pointing to the attachment itself, but to the list item that contains that attachment. But in the description of the search result, you can see the words from the attachment that you searched for. This is a bit disappointing because the search result would be confusing and useless if the list item has multiple attachments. The user won’t know which attachment contains the words he searched for.
(thanks to Saji Viswambharan)