Thank you for hearing (me) us!
IMO, adding a web option to set the max attachment size is easier to understand and more useful.
I usually set the attachment size to 25 MB. But there are situation when you need more size (I have a web app that sending emails with attached files which can reach 75 MB/email).
I think it depends on the system administrator. The sysadmin must know what is better for his system. Let’s give him a chance! ( Firewall UI for policy rules - #17 by Jim )