I would like to write a plug-in that will allow a custom written CRM to read and write to their local Outlook client. I know that this poses a security concern. But, my clients are asking that their CRM "be connected" to Outlook. They would like to be able to do the following:

A) When a contact sends them an email (reply or free standing email), they'd like the details of this email to go INTO the CRM. Yep. They would like me to save the body, time and date it was sent, etc.
B) They want to be able to send new emails (or replies to existing emails) from within the CRM itself. Basically, "a form that looks like Outlook's send/reply email form".
C) Want the ability to search for contacts and the related emails with a search for tags/keywords facility. (i.e. if a product name or code appears in an email then they want the email returned in the search). D) Having performed a search of many contacts, they will want to prepare a mailer and shoot out some sort of email announcement to their qualified leads. This could be 50, 100, or more persons. So its got to be able to allow bulk mailing. E) Given a list of new prospects, that arent currently contacts in the CRM, they will want to do the same and if they get replies from this mailer to the prospects, the will want the replies to be saved in the DB and contacts be inserted into the DB. F) They would like to be able to utilize the calendar and task list facilities of Outlook from the CRM, as well.

More or less, they want this pretty basic (as it is today) CRM that I created to integrate with Outlook and have it do so seamlessly as if it was an add-on to the CRM. A plug-in is what I am thinking...

But, I dont know where to begin. My environment is Windows XP/Vista and is going to be ASP.NET and I am going to use the VB.NET language to accomplish this. What do I need? Are there resources out there that can describe how to build a plug-in to Outlook as I have been asked to? This is not Exchange, none of the clients use exchange (not so far). They all run Outlook. Mostly 2003. Most clients are XP right now but some are upgrading to Vista.

For some reason I cant seem to wrap my head around this. I think the whole security issue is thwarting my ability to see past what is probably a simple thing. The client doesnt want to be prompted by any security messages asking them if they are sure they want to send 382 emails to their contacts. Not once and certainly not 382 times.

Where do I begin? I've searched the internet for similar but mainly what I found are already-written products and I've got to write this from scratch.