What needs to be running for SpamSieve to work?

Sorry for this likely really dumb question, but what needs to be running for SpamSieve to do its wonderful job?

Assuming my iMac is on and logged into my account, does Outlook Mac 2011 need to be running, or does just SpamSieve need to be on? Both of my mail accounts are IMAP.

Thank you!

The mail program (e.g. Outlook) needs to be running. It will launch SpamSieve as needed.

Thank you!
Appreciate the great support