Antispam also referred to as SpamAssassin can solve your problem.
Antispam trace, filter out and delete spam messages coming to your mailbox. It doesn’t delete messages recognized as spam but only marks them as spam and delivers them in a regular way, which is why these messages also count against your summary traffic.

alemcherry thanks for advice but how can we manage antispam protection on our account

To manage antispam for the entire account:

1. Select Account settings in the Account menu.
2. Click to add antispam resource for all mailboxes or for all mail resources (box, forward, alias, responder) in this account.
3. You can delete all antispams in this account by clicking the Trash icon.

can we manage antispam protection on the mail domain level and mail resource level ?? and how can we do it

yes, u can manage antispam protection on the mail domain level and mail resource level

To manage antispam at the level of maildomains

1. Go to the Mail Info menu and select the mail domain from the drop-down box.
2. Click Go and you will see the mail service details of the chosen mail domain
3. On the page you will be taken to, add antispam either for all mailboxes of this mail domain or for all mail resources (box, forward, alias, responder).
If necessary, you can delete all antispams under this mail domain by clicking the Trash icon.
4. Clicking the antispam icon will let you configure antispam settings for mail resources.
5. Click the Submit button at the bottom of the form.

To configure antispam protection for a mail resource:

1. Click the e-mail address in the E-mail list on the Mail Controls page.
2. Check the AntiSpam box.
3. Click the Submit button at the bottom of the form.
4. On the Mail Controls page click the Antispam icon in the Resources included column:
5. Fill up the Antispam preferences page
6. Click the Submit button at the bottom of the form.