>>>>I re-read the customer message and I think I understand the issue better. Let me explain to you and Borislav to see if there is a solution:
>>>>
>>>>The customer - for security reasons - restricts the use of SMTP. Therefore, they control access on the Exchange server via a list of authorized IP addresses. Therefore, they assign a bunch of static IP addresses for PCs using my application and enter those IPs in the list of authorized (on the Exchange server). Therefore, in their case, if a PC changes the NIC or PC itself gets replaced, the user has an issue emailing. And we have hit this problem a couple of times already. So they want to know if my application can send email from the server and not from the client PC. I suppose the SMTP will be the same but initiated on the server instead of on the client PC.
>>>>
>>>>Now, does it make sense and is it possible to do what they want?
>>>
>>>Perhaps the user-side of your application might save pending e-mail requests to some kind of DBF or other structure, and a separate process on the server regularly checks for unprocessed (unsent) records, i.e., e-mails.
>>
>>I thought about this approach too but it seems like it will be complicating things quite a bit. I would have to write a program that would be running 24/7 on the Server monitoring this .DBF or some other file and process requests to email. The downside of this - for me - is maintaining this program and dealing with issues such as the program shutting down (when server reboots) or some other issues. Thank you for your help.
>
>Other way is to make them to set up security not by IP but by MAC address of the used LAN card.

True. But LAN cards and MAC address change too. I find that more and more of my clients start to restrict or outright ban use of client emailing to SMTP. And I don't see an easy solution. Thank you.