Live Mail is adding data to incoming attachments

Good Morning...

I send attachments home regularly from my design work station.

The attachments received are significantly larger than the ones I send.

An 8 meg file will show up as 11.75 meg in my [in] box. This is annoying, due to

the slow download when over the 10meg delimiter. For this reason...anything larger than 10

meg...I will generally put on a flash drive and hand carry [instead of Email].

I will point out, that this was not an issue on the XP 'Windows Mail' I was using up until last year.

What information is being added? Is it specific to Windows Live Mail?

Can I change this? Is it part of the [Mcafee] security scan?

Thank you for any input...

Jay