How to use server with CWP as email server

I have a new server that will host a mautic instance (it's a plataform for send newsletters) I want to send the email directly from that server, but  need to have everything correctly configured to prevent the emails from go to spam.

This server will only sent newsletters emails the transactional emails are sent from the main server that host the domain, what should I do in this new server to be able to create a dkim that I will add to my dns?

Should I create a new user account and add the domain localy? But if I do it the dkim generated will be have the default name "default._domainkey" but this is a problem because this is also the dkim from the main server that is also running cwp.

I have a new server that will host a mautic instance (it's a plataform for send newsletters) I want to send the email directly from that server, but  need to have everything correctly configured to prevent the emails from go to spam.

This server will only sent newsletters emails the transactional emails are sent from the main server that host the domain, what should I do in this new server to be able to create a dkim that I will add to my dns?

Should I create a new user account and add the domain localy? But if I do it the dkim generated will be have the default name "default._domainkey" but this is a problem because this is also the dkim from the main server that is also running cwp.

Did you check MailServer Manager option in cwp?

I have a new server that will host a mautic instance (it's a plataform for send newsletters) I want to send the email directly from that server, but  need to have everything correctly configured to prevent the emails from go to spam.

This server will only sent newsletters emails the transactional emails are sent from the main server that host the domain, what should I do in this new server to be able to create a dkim that I will add to my dns?

Should I create a new user account and add the domain localy? But if I do it the dkim generated will be have the default name "default._domainkey" but this is a problem because this is also the dkim from the main server that is also running cwp.

Did you check MailServer Manager option in cwp?

Yes but I don't have any option to generate a custom dkim with a specific selector.
I have added the domain on the server that will send the newsletters it generate a default_domainkey I can't have 2 dkim keys with the same name on the dns. My solution at the moment was to copy the dkim keys from the original server and paste it on this server.
So both servers have the same key and I need a single dkim record for both, but this is not a perfect solution should be possible to customize the selector used to be able to create something like newsletter._domainkey and prevent problems in dns

It is possible and we have used that in past.

https://serverfault.com/questions/922197/can-i-use-multiple-selectors-for-opendkim

Did you try this?