Work trying to block e-mail clients

Hi there,

I work several jobs and to keep them all organized I have historically used Thunderbird mail client so I can easily have access to and respond to my e-mails. I've done this personallly and professionally for years.

For reasons I can only chalk up to someone got paid to shill this, at one of my jobs that I've barely worked for since the pandemic began, the entire organization recently began a mandate forcing EVERYONE to only use Microsoft everything. This has screwed up a bunch of things, despite our existing processes in place, and made it far harder to access many important documents and records (some of which had to be deleted JUST because they were Google Docs or placed in a non-Microsoft location). They've even delivered a hard edict that we can't work on anything non-Microsoft related for the company. In general, it's made everyone's job a nightmare, especially from home, since some MS stuff doesn't match how most people work and has its own issues.

I recently got an e-mail from IT saying they can tell I use a Mail Client (Thunderbird) for my work e-mail and I have to either stop using a mail client and access my e-mail using the glitchy web portal (which I have no reason to ever check) or use the Outlook mail client which I have to buy (which makes no damn sense except for shilling). It was supposed to happen a month ago, so I took it as an empty threat, but as of today, Thunderbird can't access my e-mail account anymore and claims its credentials are wrong when I've confirmed they're fine.

Given how rarely I work there now, I really don't want to have to bother checking the web e-mail portal considering how often it messes up and how much of a hassle it is to keep track of amongst the many other e-mails I parse through daily for all my other jobs. I don't want to get in trouble for being unresponsive because the org thought it was a good idea to willfully scramble all their communications because Microsoft paid them to.

I'd like to know if I can hack my way around this and find a method that hooks this work e-mail back into Thunderbird so I can continue using it there. Would greatly appreciate any help figuring out a fix.