If you must do this in Informatica PowerCenter, below is a possible solution:
Create a mapping with a mapping variable (say var_m_F_COUNT(int)). Using a aggregator transformation count the number of Fs and set the variable with the count.
Now create a workflow as follows:
start ---> assignment task ---> session ---condition---> email task
Create a workflow variable (say var_wkf_F_COUNT). In the assignment task set var_wkf_F_COUNT = 0.
In the session, in Pre-session variable assignment, assign var_m_F_COUNT=var_wkf_F_COUNT
. In post-session on success variable assignment, assign var_wkf_F_COUNT=var_m_F_COUNT
.
Now, double click the link to the email task(for 'ALERT') and write the codition var_wkf_F_COUNT>0
You can create another email task with the link condition as var_wkf_F_COUNT=0 for 'PASS'