On Sun, Dec 03, 2017 at 09:48:02AM -0800, Michael S. Singh wrote:
Will I also need a static IP address in order to connect to the server from anywhere in the world?
Yes. And it will need to be located in an allocation that's known to be static, i.e., a single static address in the midst of a large block of dynamic addresses == trouble. It'll also need to be on a provider that that has scrupulously dealt with abuse issues; those that don't may have large swaths of address space that's already blacklisted. One way to determine this is to ask them what address they will assign *before* you sign up, then check that address against various blacklists. You'll also need matching A and PTR records: if the mail server is mail-abc.example.com, then the PTR needs to match. It's also highly advisable to make it HELO as that same canonical name. I also suggest running an instance of a nameserver on the same box. Mail servers make a lot of DNS queries, so having one right there -- with a cache that will eventually be populated according to local usage patterns -- is useful. Just make sure it's not an open resolver, i.e., make sure it only answers queries on 127.0.0.1 A Raspberry Pi can handle this. Doubly so if you customize its defenses specifically to your needs. The more abuse you reject outright via the onboard firewall and via MTA configuration, the less will make it through to more computationally expensive steps. Note that you'll need enough storage if you really do plan to use it for the LKML; I've seen roughly 50M in traffic on it since 11/28 and there are times when it spikes (in terms of the number of messages and their aggregate volume) quite a bit. ---rsk