Receiving error when attempting to update Slack email to one associated w/ deactivated account

Question

TL;DR Version: On slack, is it not possible, for a workspace member (not a workspace owner or admin) to update their email to one that belonged to a former member who deactivated their account?

In other words, are the emails associated w/ deactivated accounts added to a sort of "blacklist"?

The owner sent me 2 invites (the initial invite went to an unpreferred email) & despite unknowingly joining the workspace via the unprefferred email on my desktop, I did some things that I'm proud of & want to keep under my name. A couple days later, I signed into the workspace using the preferred invite on my phone & after noticing that my joined channels & direct messages were missing (& that there were 2 members w/ my name now), my mistake was realized.

I deactivated the account on my phone (preferred email but undesired account progress), waited a while, then on desktop (unpreferred email but desired account progress) I chose "Sign out all other sessions", attempted to update email to the preferred one, but received the following error: "That email address is being used by another account". Intended functionality or a bug?

Answer 1

No, this is not a bug. Slack uses the email address as primary key for your account.

So if a user has previously been invited with an email address, you can not invite another user with the same email address or change the email address of a user to one of another user (dactivated or not).

If you really want to retain that specific email address you can try the following:

First change the email address of the deactivated user to something else and then try to change your email address to the one your wanted.

Or request to fully delete the deactivated user account. That will include the deletion of the email address. See this post for details.