I would suggest not to use Atomic wallets as it has been compromised.

Secondly given them the USDC public wallet address is safe because no harm can be done if you give the public address to anyone. Only you need to safe guard your private key and i am sure you are already aware of it.

By the way, i still not get why did you got this email from the Atomic Wallet ? What will they make sure even if you tell them your public address