This dll file is essential to the add-on for Outlook Express that handles faxes and it’s absence or corruption may generate unwelcome errors .A common cause of this is mistaken identity. Many anti-virus programs mistake this Windows dll file for malware and delete it. This problem is usually fixed by running a decent Registry Fix utility to replace or repair the corrupt or missing file. Failing this you can find the file via Google online and then download and install it.
If you do not make use of Outlook Express’ fax capabilities simply delete the add-on. The less tampering you have to do with dll files the better.