More testing...
I went to my Yahoo acct and sent a test email to my main identity (Bellsouth ISP). It comes thru just fine. Then I sent another test email from my Yahoo acct, added the attachment (dam.pdf - 72K in size), Avast sounded the alarm as it did yesterday.
Next, I turned off 'Internet Mail' provider of avast and sent another email from Yahoo with the same attachment (dam.pdf). The email came thru, but there was no attachment! I do have
"Do not allow attachments to be saved or opened that could potentially be a virus." selected in my OE-6 mail client. But I think the attachment was converted to text because it's included in the email itself and looks like the 'source' file and very long.
I'm sure it's not a false positive by avast because after downloading and scanning it with avast, it comes back clean. Besides, I had VirusTotal scan the pdf file (Jotti is too backed up) and it comes back clean by all 31 AV tests.
Next, I send another email from Yahoo... attach a different file (Word doc) and I get the same alarm... Heuristic detection,
Multiple Content-Type header - HIGH DANGER!. I click 'continue' and allow the email thru because I know it's safe. Even the word doc attachment is gone. Again, it's changed to text.
Not sure what's going on here.