Cart Abandonment Solution for Marketo

I think you need to define "seamlessly."  Describe the full extent of your fantasy integration with Marketo/Munchkin/Forms and some things you consider, er, seamful.

Bottom line, most CA solutions expect to manage email campaigns with abandoners.  Their primary function thus distinctly overlaps with Marketo's primary function, so you have to locate how the two can be complementary, rather than redundant and confusing.  (And see if you can pay only for the complementary part of the CA software.)

There are several tools on launchpoint.marketo.com.

What is your ecom solution? That might help you understand where it is best to use that tool and CA and then route emails through Marketo. Just because you have Marketo does not mean it is always the best place to do something.

In general, I would try to send all emails from Marketo to avoid confusing customers' servers, but maybe that's not realistic in certain situations like order processing vs. the time it takes to figure out how to do it in Marketo.