I have had the same email address for 20 years, say a@a.
10 years ago i created a website for me, with the email address b@b. All mail to b@b is forwarded to a@a, with the plan to one day phase out a@a.
In Outlook, even though my Outlook account is a@a, I have the option to modify my name AND the email address the recipient sees, so I show them only b@b, even though I am sending the email from a@a.
All was fine until I started using Aquamail 2 years ago, and now people are seeing a@a on Aquamail and b@b on Outlook, because the option I have on outlook does not exist on Aquamail. It's really a problem. Thanks.