That way your users can create their vacancies with the ISP portal,
But then internal e-mails need to go out to the ISP, don't they? Because, if internal e-mails get delivered locally, the vacation autoresponses on the ISP will not trigger, will they?
Hello R, I only wrote about the incoming side - of course, you also want to send mail to remote users, and that includes users with an address of …@myisp.com. They will go to the ISP and be fetched to local from there.
That is not what I had in mind. My users will not go to the ISP and fetch their e-mails from there. They will always go to my internal mail server. If a user is on the road, he/she will connect with OpenVPN first.
Of course, immediately receiving new e-mails without a VPN connection would be more comfortable. But that level of comfort needs a real mail server consultant then. 8-)
The trouble is, with that configuration, if the Internet link goes down, internal e-mail stops working too.
And if internet's down, e-mail will stop working anyways, so why bother? Even facebook/whatsupp will stop working then!
I have seen Microsoft Exchange setups that carried on working locally if the Internet connection was down. If Microsoft can do that, I want to have it too. 8-)
Whatsapp (which you shouldn't actually use for confidential business communications) may continue working with your mobile phone data connection.
With some tinkering, you can configure your local relay smtp to deliver those locally, but if your people do not talk about their vacancies over the water cooler, then they will miss that reminder then.
People are not that careless even in small businesses, where there is no water cooler at all. Most of them do set up autoresponders, so that customers know. Small business tend to care about customers more than big ones. The idea is that those autoresponders should also work internally.
I just learnt that you can install a "Managesieve server" plug-in for forwarding and autoresponders. That would be the way to go then, instead of using the autoresponder at the ISP.
Best regards, rdiez