I recently bought a new Dell desktop and upgraded to Windows 8.1. I successfully transferred all e-mails and contacts from Outlook Express. I can send and receive e-mails BUT, when I try to send an e-mail with an Excel (.xls) attachment to 7 recipients, it just seems to disappear into the ether. When I phone any of the 7, they have not received it.

I get no error messages, the file goes into the Sent box in Windows Live Mail.

I've checked all the e-mail addresses.

When I go into Talktalk webmail, I managed to send the same e-mail with attachment to 3 of the 7 as a test.

I can successfully send the e-mail with the attachment to my wife, using WLM. It is received back on the same PC.

I am bewildered - the problem seems to be about multiple recipients, rather than the attachment.

Can anyone throw any light on this? I was making good progress with the new PC until this point, but have spent hours on the web and on the phone to Talktalk without resolution.

It would be greatly appreciated.