Notification of address change (for external accounting software)
Use a combination of smart groups, tags, CiviRules, and CiviReports.

A. Create a Smart Group


Use Search Builder to search for Contact :: Envelope # :: Not Empty OR Not Null OR > 0
From search results, create new smart group (called "Has Envelope #")


B. Create a tag called "Update External Address"

C. Setup a CiviRule


Create a Rule with the Linked Event as "Address Changed"
Linked Condition is "Contact (not) in group", "In one of selected groups", "Has Envelope #"
Linked Action is "Add tag to contact", "Update external address"


D. Create a Report


Create a report off of Constituent Report.
Filter the report to look for contacts tagged "Update External Address".
Setup report for email delivery (if needed).


E. Office manager runs the report at her discretion (or gets emailed the report) and updates the addresses in the external program.

F. Once the address is updated in the external program, untag the relevant contact.