One may think that making changes to the e-mail address of a mailbox is a simple thing, but Exchange does a bit of work to ensure the changes are correct and will not cause problems in the system. ...
Updated Jul 01, 2019
Version 2.0
Blog Post
Can you think of any reason why moving a mailbox enabled user would cause the following:
Existing Primary SMTP Address demoted to secondary and new Primary SMTP generated (appended with number to maker unique) ie
before move:
Primary SMTP: Joe.Bloggs@MyDomain.com
Secondary smtp: none
After move:
Joe.Bloggs2@MyDomain.Com
Secondary smtp: Joe.Bloggs@MyDomain.com
Existing Primary SMTP Address demoted to secondary and new Primary SMTP generated (appended with number to maker unique) ie
before move:
Primary SMTP: Joe.Bloggs@MyDomain.com
Secondary smtp: none
After move:
Joe.Bloggs2@MyDomain.Com
Secondary smtp: Joe.Bloggs@MyDomain.com