There are pros and cons to using special characters in email subject lines. Generally, marketers report higher open rates.
Some report better engagement, but many don’t.
There are also reports of special characters causing problems with deliverability, mostly because spammers became very fond of special characters for a while.
It helps reveal the flow of execution of your program, including results of in-between evaluations. In other words, you can see what your program is doing, and why it takes the decisions it is taking.
If something unexpected happens, the trace will show you the sequence of events that lead to it.
