I have the following setup(hardware): One root server, out in the internet with a Domain example.com pointing to this server. An intranet, inside a company, containing several PCs.
Currently the mail traffic is handled by the root server and clients (Outlook) from within the intranet can send mails via the root server. The mail retrieval is only allowed for two employees within the company, they dispatch the mails to the remaining employees via the filesystem.
So far so good. My custromer now assiged me the task to have an individual email address for each employee inside the company. This would lead to employeeA@example.com, employeeB@example.com, etc. Nevertheless, there is still the requirement, that these addresses are invisible from outside the company. My customer wants to have one single email address, e.g. firstname.lastname@example.org from which the two dispatcher employees retrieve the mails. When other employees send mails, the mail should be sent from email@example.com as well as replys to this mail should be received by firstname.lastname@example.org. Inside the company however it should be possible that one employee with the address employeeA@example.com gets a mail forwarded from email@example.com or employeeB@example.com should be able to send an email to employeeA@example.com
I hope the description of the problem is somehow intelligible. Does anyone know a good approach for this kind of problem?