The Intuit Electronic Postmark looks kind of formal and official!  

I have never provided any of my clients with a 9325 or any other proof of e-filing and I never had a client ask for one.  I print off a copy of the history form and keep it in my files for my own piece of mine.

I give them all the 9325 along with their copy...but when someone asks for proof of filing for a bank or something like that, I give them the Intuit Postmark.

Where to find the Intuit Electronic Postmark?

For 1040s, I use my own looks-like-a-9325. For the others I use the report under F12 on the E File Home Base page, Electronic Filing Reports. 

Highlight both (or more) lines for the returns, press F12, choose Accepted Returns, Print.