Quite some time ago, I needed to do a big cleanup of email aliases (I have 500+) and various
My approach was to use IMAP integration with my provider to copy all the emails down to my laptop.
I then used VBA in Outlook to create a list of source email addresses and counts - then I could update places using those emails.
In your case, i'd do something similar.
Analyse your existing emails to get a list of emails by source address (or domain).
Use that list to figure out what places you need to get updated.
Then (per Sydney1's suggestion) - forward old emails to the new address. Preferably tag it somehow so you know that it means there are other places that need to be updated.
My approach was to use IMAP integration with my provider to copy all the emails down to my laptop.
I then used VBA in Outlook to create a list of source email addresses and counts - then I could update places using those emails.
In your case, i'd do something similar.
Analyse your existing emails to get a list of emails by source address (or domain).
Use that list to figure out what places you need to get updated.
Then (per Sydney1's suggestion) - forward old emails to the new address. Preferably tag it somehow so you know that it means there are other places that need to be updated.