I'm using the built-in "Outlook Mail and Calendar" app on Win10, as my employer uses G-Suite (formerly Google Apps) and the Office version of Outlook doesn't know how to use OAuth or sync Google calendars or contacts. I have a number of aliases on that account that are different from my sign-in account (I sign in with "[email protected]" but also own "[email protected]" and "[email protected]"). I can't get Outlook Mail to send from those accounts, though! I can do it through the Gmail web app, but not through the thick client.
At a minimum, I want to change the default "From" address to "[email protected]" even though I sign in with "[email protected]"; I don't care that much about being able to send from "[email protected]" or "[email protected]". I was able to do this on the web app, but the Outlook Mail app isn't respecting this setting; it always sends from "[email protected]" because that's the sign-in address. I can't add the other addresses as their own accounts, either (not that I really want to; I'd get all my mail multiple times) because I can't sign in as "[email protected]"; it's an email alias, not a separate account.
The best thing I've found is a registry key that ought to control these settings: HKCU\Software\Microsoft\ActiveSync\Partners\{<GUID>}
. It contains values such as the following:
AccountType: Gmail
Email: [email protected]
Name: Corp Google Apps
Server: imap.gmail.com:993:1
(and many others). If I change the "Name" of the account (using the Settings -> Accounts screen, or right from within the Outlook Mail app), it changes the "Name" registry value at the above key. However, if I change the "Name" value in the registry (or the "Email" value, which is the one I actually want to change), this doesn't change anything in the app (or in Settings)! Even if I stop all processes and services that have that registry key open, and then make the change, and then restart without any of those processes launching... on the next boot, it's still using the old "Name" and "Email" values in Outlook Mail and Settings (even though my changes in the registry have persisted)!
Might be related to Change Windows 10 "from" Address GMail, though there's not a lot of info on that question (and no answers). I'm running the Insider Fast ring builds on my home machine, and am fine with an experimental or totally unsupported fix.