There are services out there that Hubspot recommends to clean your data like kickbox ( https://kickbox.com ). That could help a little bit. But longer-term instead of hiring resources for maintenance, I would recommend looking to build data workflows for maintenance of your leads to identify items that need to be attended to and see what you can automate.
The one area that I will caution you against in your posting is "adding new contacts to the database against set criteria". That is the clear definition of what spam is, which is unsolicited marketing, and if those contacts opt out or complain against your emails, if they were added manually they are not GDPR, nor CAN-SPAM compliant and could result in legal repercussions against your organization.
There are services out there that Hubspot recommends to clean your data like kickbox ( https://kickbox.com ). That could help a little bit. But longer-term instead of hiring resources for maintenance, I would recommend looking to build data workflows for maintenance of your leads to identify items that need to be attended to and see what you can automate.
The one area that I will caution you against in your posting is "adding new contacts to the database against set criteria". That is the clear definition of what spam is, which is unsolicited marketing, and if those contacts opt out or complain against your emails, if they were added manually they are not GDPR, nor CAN-SPAM compliant and could result in legal repercussions against your organization.