CRM lead capture intergration

i need CRM integration to be set up on an existing wordpress website so it links and captures new and existing clients details and email addresses. i also need all existing email enquiry addresses to be exported from office 365 outlook emails i would like the software or plugins used to be free as our traffic is not massive. the whole point of this is to capture more leads and have then put into a CRM data base so we can mail shot promotions and property listings that teh clients have enquired about. We currently haver forms that capture and use mailpoet for newsletters on our website [login to view URL] i want a system that is easy to use and will produce real results so potential clients that have made enquiries are kept informed even if they dont subscribe to our newsletters. at the moment we only have a subscribers list but this is only used to send a general newsletter not specific information of property types they enquired about. if they dont join teh subscribers list they get lost and forgotten unless they actually buy a property. i would like to send out email to all clients and potential clients for such things as birthdays christmas etc along with property information