On Tue, 2005-05-24 at 11:02 +0100, Chris Green wrote: <snip>
The question is should I simply move all my fetchmail bits and pieces from the system where I currently read my mail to my home system or should I receive the mail using SMTP?
As with most things it depends, although many would likely say that SMTP all the way is best - it is certainly cleanest.
<snip>
Would it actually be easier/safer to collect all the mail using fetchmail (much of it is collected on the hosting service by using fetchmail to get it from other places) or does SMTP actually confer any advantages? It would actually be pretty easy just to transfer my .fetchmailrc file from where it is now to my home Linux box and not bother with SMTP at all.
Safer in that you have no open port 25 open to the outside world, and if you have already used fetchmail in the routing inwards then you probably don't gain anything in switching back to SMTP transportation (unless you are then splitting out to multiple accounts again, but this is where having fetchmail in the line complicates things most). The main issue with using fetchmail to collect mail is that some of the header information can be lost or not used in the process. The main situation I've come across here is when an email is sent to multiple recipients at the same domain and it is all collected via fetchmail. Generally only one will see the email without some extra form of intervention. If everything is coming into a single mailbox then there is probably little practical difference in the two methods (except you may not get two copies of a message if you have it sent to you at two addresses).
If I open up the SMTP port to the outside world what issues are there? I want to deliver mail from my hosting service which handles all mail for my isbd.co.uk and isbd.net domains, I have a web configurator which will let me forward all this mail to my home machine (which is a subdomain of isbd.net). I can thus limit connections to just the hosting service so that will probably deal with most of the security issues, I will also obviously check that relaying is not allowed (I'm pretty sure it isn't now). I will still need to run fetchmail to get mail from a few old POP3 hosts where I get the odd message still.
Limiting the IP addresses that can talk to your mail server certainly ties things down nicely, and I would personally opt for SMTP, but at the same time most of my current mail setups use fetchmail at the moment! This is partly due to current and legacy issues with dynamic IP addresses (and I've never bothered to sort out the SMTP pull setup that Demon use where you notify the SMTP server that you are on line and what your IP address is so it can start delivery - can't remember the acronym off the top of my head).
I am in the process of switching over to SMTP myself, but then I run a business off my connection as well as having around 10 - 15 domains to support in various ways (not all on the ADSL connection for all functions, some only backup/development services). My system will also be working with a mail relay in a DMZ that will handle filtering and a few low volume mailing lists.