Yes your ETA was approved. You received an email stating the expiry date of the ETA, the maximum duration of your stay, the number of entries and the conditions attached to the visa. According to the website of the Australian Department of Immigration and Border Protection, these are the details you'll find in a visa approval email:
How will I know if my visa application has been approved?
We will tell you.
If the visa is granted, we will let you know:
- when you can use the visa
- the visa grant number
- any conditions attached to the visa.
If the visa is not granted, we will send you a letter or email advising:
- why the visa was refused
- your review rights (if any)
- the time limit for lodging an appeal (if applicable).
If you are still unsure about whether or not your ETA was approved, you can use the appropriate official online service to check its status.