Outlook 2016 Send from Outlook Alias Account?

I get so furious with Microsoft. Having wasted hours looking for a solution that will allow me to create aliases on Outlook 16 I cannot find any easy solution. Creating different e-mail accounts just creates lots of clutter and wasted time when all I want to do is have ONE inbox yet have the facility to use different e-mail personas for sending and receiving for the different aspects of my business. For a multi-billion dollar company it reflects poorly on the needs of its clients.

You actually create the aliases via your online account.  (This assumes it is a Microsoft account - outlook.com, live.com, or Hotmail.com)  Sign into outlook.com and create your alias via the "Settings" gear icon, "Connected Accounts" item.  Create your desired alias(es).

At this point, when you go into Outlook 2016 and compose a new message (or reply to an existing one), your "from" button will be a dropdown list of the accounts which can be used to send the mail, including the alias(es) added on outlook.com. 

At least, that's how it works for me.

The problem with this approach is the recipient sees the email sender address as a bunch of letters/numbers at outlook.com on behalf of correct email address instead of from correct email address. Doesn't look good - maybe OK for kids and no-professionals but not for businesses with their own domains.

Also, in my case, I have an Office 365 Outlook account for work as well as 2 Outllook.com accounts for personal. Even if you set the personal accounts as default send from in Outlook desktop, the work account is always used for Sent Items (even if the email address in this case is the personal account). And then you can't move the personal email from the work sent items folder into the personal one because Exchange Active Sync does not support that!

It seems Microsoft have found every possible way to run multiple accounts and turned the all off out of spite.

I am not seeing that behavior.  I've sent from an alias to both Microsoft and non-Microsoft accounts (Comcast.net) and each had only the alias in the 'from' box.  In the Microsoft account case, both the sending and receiving accounts have the Exchange backend.  FWIW, the sending account was recently converted, while the receiving account is new enough to have been born with the Exchange backend.

Here you go

I've always had this "outlook_string at outlook com on behalf of the desired email address" behaviour - both before and after the upgrade to EAS. That's what I avoided by using Linked Accounts. However, now post-upgrade, Connected Accounts don't save sent items in the Sent Items folder so I tried alias again in Outlook.com and it's still the same. "on behalf of" doesn't cut it when using it with sites expecting your desired email address and/or clients who know you by desired email address.

And, as it happens, I have an inbound email from a correspondent to whom I have previously sent from an alias - in her reply to me, you can clearly see the "on behalf of" nonsense I don't want:

If they hadn't broken Connected Accounts Sent Items folder, this wouldn't have mattered. But they did. Now, there is no way to use a non-Outlook domain with Outlook and have your outbound emails a) look as if they come from your domain and b) get saved in the sent Items folder.

I've always had this "outlook_string at outlook com on behalf of the desired email address" behaviour - both before and after the upgrade to EAS. That's what I avoided by using Linked Accounts. However, now post-upgrade, Connected Accounts don't save sent items in the Sent Items folder so I tried alias again in Outlook.com and it's still the same. "on behalf of" doesn't cut it when using it with sites expecting your desired email address and/or clients who know you by desired email address.

I think this is related to the way you added your alias in outlook.com or, to be more accurate, to the way you did not setup the "desired email address" in outlook.com in such a way you can send message with.

You'll find explanations is these great articles https://www.msoutlook.info/question/outlookcom-with-custom-domain-from-address or https://www.howto-outlook.com/howto/outlookcompersonaladdress.htm.

What you need to focus on is the process to have a "connected account". If were you, I would try to remove the faulty accounts from your list (here: https://outlook.live.com/owa/?path=/options/connections) and setup them again from scratch. It seems the connected accounts are not always correctly migrated from the previous outlook.com to EAS.