Hi all -- I'm trying to set up a friend's Gmail account to pull email from the email address I've set up for a non-profit he runs. In Gmail, on the account settings, I only seem to be able to add POP3 as an import option:

Following that, I'm using the documentation here: https://docs.opalstack.com/user-guide/email/
Incoming Mail (POP3)
Server hostname:
United States: **mail.us.opalstack.com**
Germany: mail.de.opalstack.com
Username: your mailbox name (not your email address)
Password: your mailbox password
Authentication type: Normal password (some clients show this as just "Password")
Secure port - SSL: 995

I'm using my username and password for the mailbox, and I think the right mailbox URL (it's a US box) and the SSL per the above.
When I click Add Account, I get
There was a problem connecting to mail.us.opalstack.com. Server returned error: "Connection timed out: There may be a problem with the settings you added. Please contact your other email provider to verify the correct server name and port."
Is there something I'm missing here?