I have been using Windows based hMailserver but now need to move this to linux.
I have installed Postfix on Alamlinux 9 and it is working for sending from the server itself. (Using a VPS from IONOS)
My requirement is to have only outgoing mail for remote users. There are no local users other than the server itself - sending from php and the like.
We have users of our bespoke software who need to send out batches of emails (like statements and remittance advises) and we provide the mail server for that to happen.
So all we need are accounts (one for each of our clients) so that our software can authenticate with the server and then send the email.
There is no incoming mail. There is no need for a ‘sent’ folder.
Our clients will not be logging into the server to look at their accounts (there will be nothing to look at!). They will not even know their own credentials.
And obviously the server must not allow anyone to send out emails unless they authenticate,.
I have done extensive googling and discovered that Postfix does not do this natively. It seems it needs SASL.
The postfix.org docs are not really for the like of me - I need some simple steps to follow.
Please could someone provide that or point me to some site I can follow.
I’m also open to any suggestion other than postfix, if there is a simpler solution.
PS: We have been using a non-standard port for incoming mail and blocked 25. I do not see anywhere in main.cf how to do this - to specify on which port postfix should listen.
Many thanks.