Looking for Email Deliverability Expert for Bulk Emailing

We currently have our own bulk email marketing company (outbound email marketing system) and need your help with fixing our deliverability rates. We are looking for someone with technical skills to improve our system. Of course, being a bulk email provider, it is almost impossible to get great deliverability rates, but we know there is room for improvement.

We have our own custom platform and MTA. Looking for someone to advise on what we can do to help improve delivery for our clients.

Currently we do the following for deliverability:

- Dedicated IP's and dedicated domains for each client.
- Have setup SPF,DKIM, DMARC and senderid dns records
- list unsubscribe headers.
- Forward confirmed matching rDNS
- Blocking all hard bounces after discovering the address does not exist from future campaigns.

Here is what we can get help with:
- Provide executable actions that can help us improve our deliverability
- Advice/consultation on avoiding spam or being blacklisted
- Insights on Spamhaus CSS
- Uncover an opportunities or issues within our setup