How to send a message to the provider effectively.

[macbookpro]

Hi, I have some questions and I look forward to your help.
I am not very happy with my provider's virus scanner so I thought about doing some additional in-house virus scanning Which I have learned on the internet to it but sending all e-mails back to my provider's mail server where they can be fetched finally through IMAP and webmail by the clients, instead of storing the mails locally at hMailServer.
So my plan is the following:
1. At the provider: Redirect all incoming mail for all users into a single "catch all" mailbox
2. In-house: Let hMailServer fetch all that mail via POP3 (looks like IMAP is not supported)
3. In-house: POP3 traffic is scanned and cleaned by first anti-virus (Kaspersky).
4. In-house: All e-mails are then forwarded by hMailServer via SMTP back to the provider's mail server (and maybe stored locally for backup if possible)
5. In-house: Outgoing SMTP traffic is scanned by second anti-virus (Bitdefender at the gateway)
6. At the provider: I plan to set up some kind of filter to be able to detect that the mail has been sent through their own outgoing servers (SMTP login) so that it is not sent to the catch all mailbox (see no. 1) but distributed to the normal user mailboxes instead.

Questions: Will my idea work at all? Is there a way to make sure that the mail sent back to my provider via SMTP is not resent to the other recipients if there are other recipients from other domains in the mail ?

Thanks in advance!