We are developing a web application in PHP, and want to be able to reliably send out mails.
Our current solution is sending mails through our hosting provider's SMTP server, but lately we have experienced problems with mails not getting sent, when sending to some of the addresses we use for internal testing. It is likely because we test the system a lot, and our ability to send to those addresses have been blocked in some way by the provider.
What is the best way to solve this? (taking reliability, price and convenience into account?).
Can we set up our own SMTP-server, not having to authenticate to anybody? We have root access to the server (Ubuntu Linux). I know nothing about how e-mail providers prevent SPAM nowadays - do you have to get whitelisted by some kind of authority to be able to reliably deliver mails? How easy is this, and which daemon is the best for our purpose?
Should we buy access to relay through a different SMTP provider? We want to be able to send with our own domain in the FROM-address. Which is cheapest and best? It should be fast when sending to addresses in Denmark. The use case is very simple, and we do not need fancy e-mail marketing functionality etc.
