Remember that avast has a working relationship with MS - avast team members frequently genuflect at the shrine in Redmond (I speak as one who used to do the same).
I doubt that avast admits to "understanding" WebDav at all given their relationship with MS. So the simple answer to your question Tech is "No".
A little more background - for those interested.
I should have been more precise when I said that WebDav has been renamed DeltsSync. DeltaSync covers what I shall call WebDav I and WebDav II.
WebDav I is the specialized http susbset created by MS to allow "paid for" or very old free Hotmail accounts to connect to the Hotmail server in Outlook or Outlook Express that gave an IMAP experience for those account users. It is now understood but is only actively "interpreted" by a few Webmail to POP converts. A few that come to mind are HotPop, Incredimail, Foxmail, and the Webmail extensions of Thunderbird.
WebDav II is the latest variant that MS created that is the mechanism that allowed new free Hotmail accounts to work with Windows Live Mail (or whatever they are now calling the latest desktop replacement for Outlook Express) but not work with Outlook or Outlook Express so that the value of paid for Hotmail accounts could be justified. Strangely during this development they originally used WebDav I for all free Hotmail accounts so that they all worked with Outlook and Outlook Express. I suspect that those paying complained (asking what were they paying for) and so they created WebDav II that allowed the paid accounts to work with Outlook, OE and Windows Live Mail but the free accounts only worked with Windows Live Mail.
This caused even more furor and (along with the inroads being made by Google with free POP and IMAP accounts) made MS think again - fast. Since then Hotmail has been giving ground in a big way. They now offer free code to allow the Hotmail free accounts to be used with Outlook (so silly that they had to invent code to undo what they did to stop them being used - but that is MS for you).
They really want the Hotmail users to go for the DeltaSync (in reality IMAP) experience with an MS client because it is easier on their servers. Nevertheless they understand antitrust law in the US and in the EU and they are now allowing "paid for" accounts to access Hotmail via regular POP and SMTP servers for Hotmail again and have committed to make them available for all free Hotmail users with in the next year or so. With this we will be back to the position before Hotmail withdrew free POP and SMTP servers access for free accounts. Who can doubt that Yahoo in the US will also have to give ground too?
