Re: Cool things to do with server
On 23/03/15 07:42, Joe wrote:
>> The only issue you might hit is port 25/tcp being blocked by your ISP.
>> > You may have to relay outbound email via their SMTP server.
> I think that's quite rare, as I still get vast amounts of malware from
> domestic connections. What is more likely is that outgoing mail will
> not be accepted by many people for a variety of perfectly good
> spam-reducing reasons.
Not as rare as one would like, as it happens. Telstra 3G connections
are one example where port 25 is firewalled off. Yes, it'll connect,
but it'll be one of Telstra's servers, not yours, that you connect to.
I found this out the hard way when I couldn't figure out why my father
had trouble getting into his email when he was accessing it via 3G.
The solution was authenticated STARTTLS SMTP on another port.
> Many ISPs don't care if their IP address blocks
> are on email blacklists, and won't make any attempt to have them
> removed. Many will not provide means of setting a proper PTR record for
> the IP address. In some parts of the world, it's difficult and/or
> expensive to obtain a fixed IP address, and while some kind of job can
> be done using a dynamic address, it's not ideal and almost certainly
> the address pool will be blacklisted, requiring the use of an outgoing
> smarthost.
Indeed, you would think they wouldn't want the bad publicity of being
blacklisted for spam. The "don't care" attitude that's seemingly so
universal is saddening, but that's a discussion for another list.
Absolutely though to run a mail server effectively, a static IP address
is really a must, although you can get by with dynamic. The only real
show stopper is carrier grade NAT, then the whole exercise becomes
rather pointless unless you only read your mail on your own private LAN.
--
Stuart Longland (aka Redhatter, VK4MSL)
I haven't lost my mind...
...it's backed up on a tape somewhere.
Reply to: