Can I setup an MX record for a particular user email address?
Solution 1:
You can't do this by indicating multiple the MX records for the same (sub)domain. The mail will be delivered to the server(s) defined by your MX record regardin only the (sub)domain, without any look at the user@... Mail routing is done on the (sub)domain part only.
Possible solutions :
You can use subdomains, to re-route easily : [email protected] . The drawback is that you have to change your email address and ask your contacts to update theirs.
However, there's nothing stopping that mail server being an application that forwards mail onto several other servers based on the user name of the recipient... i.e. tell your mail client to forward all incoming messages for [email protected] to an other mail server.
Solution 2:
No. The MX record for a domain designates the SMTP server/s which are responsible for receiving mail for the whole domain.