back in 2011 I wrote about that for pop http://thunderbirdtweaks.blogspot.com.au/2011/07/using-hotmail-live-alias-with.html

The information on not using the folders is wrong for IMAP, but the use of identities in Thunderbird has not changed.

Thank you for the reply. Are you saying that sending from Hotmail aliases works via POP3? Has anybody gotten this to work with IMAP?

No I am saying when I wrote it hotmail had no IMAP. So some of the pop only information like not using folders in hotmail do not apply.

The use of identities in Thunderbird is the main issue here. You must use them.

At the time I created identities and aliases so I could document them. I have no use at all for them, so I have not looked back.

I'm just confused as to why you thought your article was relevant here. It does not seem to address my question in any way. Thank you anyways.

Well If your not going to use identities then your not going to get your alias to work how you think it should as each identity has it's own SMTP server settings. But be confused

An Alias is not an account. it is a single account with multiple email addresses that feed into a single account.

Hi Matt. I am using Thunderbird Identities, as I mentioned in the original post.

Well it appears things have changed (A lot) in the intervening years.

I can not make it work.

Ditto that.

In hotmail I have several aliases, these are all properly configured as additional identities under the root hotmail account in thunderbird.

I send an email "from" one of these identities

The recipient gets the email FROM = primary hotmail account, with a REPLY-TO= the alias I intended.

I also have 2 copies in my "sent folder"

Basically without this working, it sort of negates the whole point of identities/aliases when the recipient gets it FROM a different address then I specified when sending.

I wish there was some recognition of this bug. It might only be an issue with Outlook.com and not Thunderbird, but it would be great to know for sure.

Here is a summary of the bug, and steps to recreate...

1. In Outlook.com: create a new alias.

       * Make sure the alias above is NOT the "Default 'From' address" set up in Outlook.com:
       * Options > Your Email Accounts > Default "From" address

1. In Thunderbird: Create an "Identity" mapped to the alias above.
2. In Thunderbird: Send an email from the identity above.
3. BUG: Email is always sent from Outlook.com's "default from address", regardless of which alias/identity was selected as the from address. (check the email on the recipient's end to verify)

have you created an SMTP server that signs into hotmail as your alias? If you can not add an SMTP for the alias, then the bug is with Hotmail/Outlook.

Wow: Even if I create a separate Thunderbird account for my alias (rather than an identity), it still cannot send from any address other than Outlook.com's Default "From" address.

I guess the bug is definitely in Outlook.com / Hotmail's implementation of aliases! I'm amazed more users are not afflicted by this.

I have tried in the past to make it work and could not. But I just gave up and used Gmail. Thunderbird support might not be good, but outlook/hotmail support is just a load of people using doublespeak that do not even know what SMTP is. They sprout corporate marketing hype like it is standards or something.