I too had a similar incident happen a few months back from my Hotmail account, which has no phone or email client configured to access it. Web access only for that account.
I think the vector is via someone else's infected computer/email client. The address book is harvested and then email(s) is/are sent from various users in the address book addressed to all the email addresses in said infected email client's harvested address book. Either that, or a mass email I was cc'd on was picked online by TCP/IP sniffers or an infected server. Either way, I did not have record of the email sent from my account, which means it was likely sent via some spam SMTP/Zombie server somewhere, spoofed under myname@hotmail.com.
The story seems even more likely when I looked at the cc list on the email sent to look as it came from me. Many of the people I knew, but a lot I didn't. And people that I emailed most were not included, such as you fine Action jArks.
Either all that above, or eLzar has gonorrhea of the mouth. Probably the latter.
My two cents.
D>M>