You can't split different e-mail addresses in the name domain to different e-mail providers just by the use of multiple MX records.
You can have multiple MX records, but they will apply for the whole domain, and mail will be randomly split between the servers those records point to.
Likewise, you could also have multiple A records for the names given by the MX records, but the result would be the same.
What you could do is point all traffic to one or more servers, and then have those servers transmit mail to other servers based on the destination address. For this:
You would need each of the "final" servers to be able to accept mail for that domain (at least for the intended e-mail addresses). I would expect quite a few providers to balk at doing so when the MX does not point to them, but YMMV.
You would need a server that can sort the mail and then redistribute it to the "right" server through some sort of manual configuration.
You would also need the final servers to be willing to accept mail from that intermediate server, which is is not listed as one of the permitted senders of for the origin domain. Unlikely with commercial providers (unless of course all e-mail you want to receive comes from a single domain you control).
So possible if you control all servers, quite unlikely if you want to use commercial providers.
The other alternative is to use mail forwarding. You will need different addresses/domains on the "destination" servers, and have the server(s) which are registered as MX for your domain forward the mail accordingly.
DNS:
example.com MX 1 my-mx.example.com
my-mx.example.com:
[email protected] -> [email protected]
[email protected] -> [email protected]
Again, this may cause issues for mail origin verification (SPF/DKIM/DMARC...), careful configuration is on order.
Then there's the issue of sending e-mail from the "original" destination adresses.
An alternative is to use sub-domains. Instead of [email protected]
and [email protected]
you could use [email protected]
and [email protected]
. Those can most definitely have different sets of MX records and different e-mail providers. In DNS/E-mail, subdomains are considered completely separate domains.