When SigParser is adding a Contact or Account to a CRM it can set the Owner of the records if configured.
If a matching Account was found the owner of the matching Account will be used.
If multiple matching Accounts are found with owners then the best match will be based on which mailbox the contact was found in compared to the owners of the Accounts.
If an owner still couldn't be determined then use the contact's strongest relationship to find a user in the CRM.
If an owner still couldn't be determined then the most active mailbox will be used to find a user to make the owner.
If an owner still couldn't be determined then any of the mailboxes the contact was in communication with where the user also exists in the CRM will be used.
SigParser won't change the Owner of an Account if the Account already exists.
If SigParser is creating a new Account it will use the owner assigned to the Contact.