USA Organizing incoming invoices

[Jennyintexas]

I'm the AP Clerk for a Houston based company, we're sorta in the oil and gas industry. We have 5 plant locations, maybe 500 employees give or take. Each plant has a buyer or two and I am in the main office. I'm the only accounts payable person at my company. I receive all the invoices, match them to PO's, post invoices, cut checks and mail them. We're going to ACH later this year.

We use Global shop solutions for our accounting transactions. I use Outlook to receive all my invoices from vendors. We have several hundred vendors... I post maybe 1200-1500 invoices a month.

I have many many Outlook rules created to help me organize the flow of incoming invoices. But I have too many rules. And I can't sort the rules. Sometimes Outlook will have hiccups and my 'rules' dont act right. Too much detail to go into.... but my question.....

....Are there any reasonably priced software/apps out there designed to manage a heavy load of incoming email and that has tools to help manage the invoices? Its not just as simple as sorting by date, there are different payment terms, priorities... some are utilities... it all depends. I'm a one woman show as far as payables. My outlook is straining under the large data file but i really need all the rules to help me.

I've been here a number of years, if I make suggestion about something that might help me in my job, I might get it approved. But I'm unsure if there's anything besides outlook to help me organize the flow of invoices.

Thanks in advance!