Redirected message and "A connection attempt failed" error when migrating from GroupWise (4347866)

When migrating with On Demand Migration for Email (ODME) from GroupWise, you may see an informational message about a redirection, followed by errors/warnings about ODME being unable to connect to the GroupWise server:

Redirected from 'https://po1.example.com:7191/soap/' to the different post office address 'https://10.0.0.1:7191/soap/'

Followed by:

[1/2]Error detected, attempting retry 1 of 3 A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 10.0.0.1 :7191 (A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 10.0.0.1:7191)