When I try to send a new email in Microsoft Outlook I get the message ‘An unknown error has occurred. Please save any existing work and restart the program (Account: ……., STMP: …….., Error number: 0×80070057)’. However, if I have an email to reply to then Outlook works perfectly. I am running Office 2000 on Windows 98 and this problem does not appear to be associated with any new hardware or software. However, my computer has recently been infected with the KakWorm virus. Any ideas?

Firstly, have a look at the Microsoft Knowledge Base article titled ‘ErrMsg: ‘An Unknown Error Has Occurred’ Sending Mail’. You can find this at support.microsoft.com/support/kb/articles/Q197/9/04.ASP. This explains and solves the possible causes of the problem where your DNS Host or Domain Name contains invalid characters, or there is a problem with your SMTP server, or where there are invalid characters or words in your computer’s name. If that doesn’t solve your problem, surf over to the Microsoft Knowledge Base article titled ‘Error when sending through the internet e-mail service’ which addresses and suggests solutions for the error message ‘An unknown error has occurred. Please save any existing work…’. You can find this at: support.microsoft.com/support/kb/articles/Q197/8/77.ASP. Finally, have a look at the article titled ‘Error Message: Could not send the message’ in the Microsoft Knowledge Base. You can find this at: support.microsoft.com/support/kb/articles/Q223/4/62.ASP. Hopefully, one of these articles in Microsoft Knowledge Base should be able to fix your problem. Of course you should make sure that you have fully removed the KakWorm virus from your computer. You can find instructions on how to do this at the Microsoft Knowledge Base article support.microsoft.com/support/kb/articles/Q262/1/65.ASP.