Celoxis mail settings are no different than the settings you make for your mail account on a client like Outlook, Thunderbird, etc.
To verify,
- You must have created an account on your mail server for Celoxis say celoxis@acme.com
- Now, create an account in any mail client like Thunderbird or Outlook whichever is setup at your end.
- When doing the setup, for the incoming mails set the address as celoxis@acme.com and set the Outgoing mail address as celoxis@acme.com
- Now, try sending/receiving mails to/from this account.
If you are not able to do this successfully i.e the mails are not sent or received, then it means that the mail account is not setup properly on your mail server. You need to contact your mail administrator regarding this.