I received a strange letter from bittrex.com

[freedomgo]

What is it an "unclaimed balance"? This is just a non-sense...how did you "claim" a balance?
Of course, no doubt this sounds just as a scam. (yes ask a moderator to move in the proper section).
Another check =

I suspect the purpose of their email was to show they're supposedly looking after users' balances. For example, if a user forgets they have money in their bittrex account and doesn't withdraw it, they'd reach out to remind them. But in OP's case, since he's sure he has no balance, this just confirms the email is actually a scam.

if you access on exchange and this don't show what they are claiming on email yes its just a scam. if you have doubts ask to their support.

The exchange has already cease their operation a long time ago, so there's no active support anymore.

[Z-tight]

Hi OP,

Just for the sake of doubt, I have received the exact same email on the same day with the same balance figure.

I believe the scammers are just sending phishing emails to leaked addresses they have in their possession. Just to ask, did you have any bittrex account before they ceased operation, because i am sure the scammers do not even know if the persons they are sending emails had any account on bittrex or not, they are just throwing their net into the river, lol.

[bitbollo]

...
The exchange has already cease their operation a long time ago, so there's no active support anymore.

They are still active, I guess you're mentioning US site that yes this one has closed activities many years ago - and now completely closed/bankrupted.
https://www.reuters.com/legal/litigation/bittrexs-us-wind-down-approved-bankruptcy-court-2023-10-30/

bittrex.com (global web - formerly bittrex international - site of the exchange) it is still accessible.
This site is target (actually) because many years ago they send similar emails for claiming delisted tokens...
Never seen something branded with kraken or binance just to mention another 2 big exchanges.