Email aliases stripped when collecting mail by Exchange

[ItsRKM]

Until recently I have collected email from the server using Outlook2016 using POP but, in preparation for Basic Authentication being deprecated in October, I switched to using Exchange on Outlook, because it is the only method that Outlook supports with Modern Authentication.  However I notice that this strips off the actual address that emails are sent to and replaces this with my primary address.  So all alias email addresses, which were retained by POP collection, are lost when using Exchange.  How can this be fixed?

The reason I use alias addresses in the first place is to simply and quickly identify compromised online accounts.  So, for example, when I opened an Amazon account I linked that to an alias email address, amazon@mydomain, rather than my primary email@mydomain. If I ever get spam addressed to amazon@mydomain then I know the account has been compromised, either by hackers or by Amazon selling my details (I’m not suggesting Amazon would, but some companies certainly do, possibly by their financial administrators when being wound up).  So my primary email has, literally, hundreds of alias addresses and, over the years, this has successfully identified several online breaches.

However this simple security procedure won’t work any longer due to Exchange replacing the “To” address with my primary address.  So, when I now get an email from Amazon, even legitimate ones,  it appears in Outlook2016 to be sent to email@mydomain instead of only the alias amazon@mydomain address that Amazon know about.  Apparently, this is a well known bug in Outlook and Exchange which has remained uncorrected for years.  😞 

Can anyone suggest a fix to ensure Outlook respects the original, alias, “To” address these emails are sent to, when collecting email by Exchange, just as it did with POP or IMAP?

[#2 · Accepted solution]

Use this: https://www.ivasoft.com/showalias.shtml

[#3]

Unfortunately, that only shows the alias address in "Single" mailbox view. I can't get it to show the alias address in the email itself or in the mailbox Compact view.

[#4]

Hi @ItsRKM,

in fact you can get it in the email itself:

[#5]

Thanks Victor,
I must have done something wrong then. I'll have a look through.

[#6]

Hmmm. Tried to start from the beginning, by running the ShowAliasSetup.msi file again and selecting "remove ShowAlias". This seemed to be successful and ShowAlias no longer listed as an available Add-in in Outlook.

Then ran the msi file again to re-install ShowAlias. This appeared successful and ShowAlias was listed as an Add-In again. However I notice that the filename was adxloader64.dll, which is different from the AddinShim1.dll file shown in the instructions. Nevertheless, I proceeded to follow the remainder of the instructions on adding a "Received As" column.
This time every entry in the column is blank, and opening emails known to be sent to alias addresses shows only the "To:" address, without a "Received As:" box underneath, as shown in your example.
Any ideas? Is the different Add-in filename significant.

[#7]

Sorry I'm unable to assist at the moment. Try to uninstall the COM add-in and use a similar utility
https://www.ivasoft.com/showaliasowa.shtml

[#8]

Hi Victor,
My mistake, it is working correctly: on newly received emails. The blank entries on the "Received As" column and missing "Received As:" box on the emails was only for emails already received. New emails to alias addresses, indeed even to the primary address, show both!
Thanks very much.
Microsoft should license this from you, and fix what has been a problematic Exchange bug since at least Outlook2010, in my experience!

[#9]

Glad to know it works, @ItsRKM