Hi Rod,

From my understanding, this fix resolved an issue where some SMTP-level delivery receipts were NOT controlled by the user's setting. 

From my testing, when the 'Request delivery receipts by default' setting is disabled, you can still manually request the delivery receipt when composing a webmail message. This setting, and the 'Request read receipts by default' setting, simply decide whether that option is enabled by default when composing. Regardless of the setting's status, you can always enable/disable the receipt request while composing a webmail message. For example, if the setting is enabled, you can turn off the delivery receipt request within an individual message's compose window. If the setting is disabled, you can manually turn it on. 

I hope this helps to clarify!