Enable SpamSieve for specific accounts only

I have multiple accounts in Mail.app. Some are Gmail IMAP accounts and I’m satisfied with Gmail’s spam filtering. How do I disable SpamSieve for these accounts, or enable it only on the accounts I want to be SpamSieved?

When creating the SpamSieve rule in Apple Mail, instead of having it say “Message Type is Mail”, make the conditions say “Account A, Account B, Account C, etc.” listing all the accounts that you do want SpamSieve to filter.

To clarify, the rule should have one line for each account. The first pop-up menu should say “Account” and the second should have the account name, e.g.:

“Account” “Account A”
”Account” “Account B”
”Account” “Account C”

At the top of the rule it should say “if any of the following conditions are met.”