Mail sending msgs I never sent

Hi there
I opened my MacBook this morning and checked my Mail
I have a gmail and a hotmail set up on the Mail application, and there had been an email sent form both emails to random people on my contact list and there was a link in them, I did not send these emails or even visit sites with those URLS.
I sent out an email to the people it sent to to not open up the link.
Then there was about 3 emails with subject Delivery Status Notification(failure)
And for 3 of the recipients it said delivery failed, but then the link was different in those emails?
I am a bit wigged out by this as of hearing about that new Mac flashback malware.
I ran a program to check if I had the flashback but it said I didn't, and am downloading antivirus software right now, but whats with the emails? What should I do?
I need to check my bank but I won't until I know it's safe to do so on my computer.
Please help!
Cheers
Darlene

Hi and welcome to M-F.

ll the advice i can give you is to change your email Password straight away. Make it passphrase or at least a 10 digit/numeral/symbol mixed up one as much as you can.
There is not much more we can give you. Dont dl any AV as it will bog down your machine and its not necessary as long as you have done a SU and have downloaded the latest Java update.
Hope all goes well for you.

Cheers

Double post

Thanks TattooedMac
Have changed all passwords to all accounts I have that I can think of.
Why do AV programs bog down your computer??

Why do AV programs bog down your computer??

Click to expand...

Because they intercept incoming and outgoing traffic plus every time you save, copy, or move a document or data. It's the way they work. In other words, the AV program is constantly scanning everything that goes on. That takes time and resources away from the system.