Email sending approaches

Question

Hi All,  in my project have to suggest email sending approachs to my manager. As a part of design document.
Following are the approachs available. Kindly share ur views on pros and cons for these approaches
Approach 1: Use third party SMTP
Pros: Readily available
Cons:Costs

Approach 2: Host own SMTP on Windows Azure
Pros:
Cons:

Approach 3: Using Public email Account
Pros: No additional cost or dependency.
Cons: Requires more effort in terms of designing and implementation.