The hosting provider is very important. It’s recommended to choose a hosting provider that does nothing else apart from hosting. If you understood the whole point of this guide and the principles that drive the development of honest free and open source software, you will avoid the hosting services offered by the well-known tech giants.
You should choose a hosting provider with a good reputation, that offers good quality VPS/dedicated servers, at low prices. If it’s a VPS, be aware to choose a VPS with kernel-based virtualization (KVM), where each VPS has its own kernel, and not container-based virtualization (OpenVZ), where multiple VPSs use the same kernel, which can’t be upgraded by you, customized, etc.
We can recommend Linode and OVH, but there are other hosting providers equally good. We have no affiliation with these hosting providers.
As mentioned before, to host all the applications described in this guide in proper conditions, you will need a VPS or a dedicated server with at least 2GB of RAM, 1 CPU core and 40 GB of SSD storage. If you intend to host many websites with high traffic, like tens of thousands of unique visitors per day, you should choose a VPS/dedicated server with higher specifications. It’s good if the provider offers both IPv4 and IPv6 addresses, although IPv6 is not mandatory. Also, when you rent the server, the provider should allow you to choose Debian 10, 64-bit as operating system for the new server and should install it automatically, so that after a few minutes you can receive the log in credentials and start installing applications. Almost all hosting providers offer the latest stable version of Debian as an operating system for newly rented servers. If they offer other Linux distributions but not Debian, this is a sign of poor quality services and you should avoid them.
After you make your choice, the first thing to do is to read their ‘Terms of service’ and check if they block ports 25, 465 and 587. Some hosting companies block outgoing traffic on these ports, in an effort to prevent spam. In general, even if they block these ports, they are willing to unblock them after you open a support ticket and explain that you intend to host a mail server that needs those ports open and that you intend to send only legitimate emails that comply with all the anti-spam regulations.
Hosting providers can also impose other restrictions. For example, they may restrict the number of emails that can be sent daily. Therefore, you should check their ‘Terms of service’ or ‘Terms and Conditions’, to learn if there are any restrictions that apply in your case and if they can be lifted.