If you are using a third party mail server (rollernet.us) which is then just forwarding to your mail server, then you don't want your server in the MX records do you? If the MX record is your server then that wouldn't work because you have port 25 blocked.
Your MX record should just be that of the mail server that you are using at rollernet. Therefore the MX record will be the hostname of that server, not of your server.
Have rollernet told you what your MX record should be?
The other way of doing it would be to create an MX record using your domain name but pointing to the IP address of the rollernet mail server. So,
"then it asks for the destination host,which I type in my email server host name"
If the rollernet server is on say 11.22.33.44 then create a mail host for yourdomain.com, such as,
yourdomain.com IN MX mail.yourdomain.com
"but I have to create an A record to coincide with the mx record, but I don't know what to put in the A record"
Map the server name that you have created in your zone to the rollernet mail server.
mail.yourdomain.com IN A 11.22.33.44
So, to recap, in the yourdomain.com zone, you can either create a new host using your own domain to be an MX record which means that you then have to create an A record to resolve that and map it to the correct IP address of the mail host that will be relaying your mail, OR you can just set up your MX record to be a resolve host outside your domain, such as mailhost.rollernet.us or whatever they tell you to use.
Here's another examplem. One of the MX record for tek-tips.com is smtp-in1.nuvox.net. So, in the tek-tips zone file, there will not be an A record for smtp-in1.nuvox.net because it's not part of the tek-tips.com zone. It's part of the nuvox.net zone, who's soa is extns1.nuvox.net.
Chris.
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Chris A.C, CCNA, CCSA
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