You end up with extra steps

1. Do something, If success goto step 3, if fail goto step 2

2. Email the failure, goto step 3

3. Do something else, If success goto step 5, if fail goto step 4

4. Email the failure, goto step 5

5. Do something else, If success end with success, if fail goto step 6

6. Email the failure, end with success

Email the failure means an explicit call to msdb.dbo.sp_send_dbmail

The ending on step 5/6 could be different where if step 5 fails you fail the job and let SQL Agent handle that failure but for consistency I like this setup.

CEWII