Re: Gnus with Exim

[David Abrahams <dave@boost-consulting.com>]

"Steven E. Harris" <seh@panix.com> writes:

> David Abrahams <dave@boost-consulting.com> writes:
>
>> Well, actually that's probably enough.  I don't normally have errors;
>> it just seems like my emacs session sometimes locks up for up to a
>> minute when trying to send mail.
>
> That was my original motivation for setting up exim too. But after
> running exim for several years, I have seen sending errors arise where
> the queuing and retrying capability turns out to be very convenient. I
> run my exim daemon with a queue run interval of 10 minutes. Given that
> my queue is usually empty, the daemon does virtually no work. On the
> other hand, on the odd chance that a message can't be sent out right
> away, I don't have to worry much about attending to it later.

That's probably a good idea for me, too.

>> The only thing that worries me is what happens in the rare case where
>> sending *does* actually fail.
>
> Exim will send a message back to the sender (you) when it's ready to
> give up on delivery, or if delivery is taking a very long time. To
> discuss failure behavior, though, we need to distinguish between
> transient failures and permanent failures.
>
>> Actually, I think there's a better answer.  See the enclosed message.
>> I just need to figure out how to apply what he says there.  You might
>> want to modify your use of &/+ accordingly.
>
> I don't think the intentions are the same. While it is nice that the
> fallback_hosts option can accept multiple hosts, you have to go
> through the sure-to-fail direct DNS lookup first, wait for that to
> fail, and only then start trying the list of obliging servers.

I don't care *too* much how long long it takes as long as it's going
on in the background.

>> It's called exim-config on cygwin ;-)
>
> No, the exim4-config package on Debian goes way, way beyond the
> exim-config in Cygwin. For my setup at home in Debian, the only
> hand-tweaking I had to do was to get my ISP's unusual SMTP server port
> specified; at present, despite a few bug reports to the contrary, the
> server port is not considered to be an important configurable setting.

OK.

>> The ideal thing would be to get the fallback stuff working.
>> Unfortunately I have to take my computer down the block to test it ;-)
>
> I have the fallback stuff set up on my computer at work ("=" for
> "fallback on FAIL only"), but the fallback scenario never gets
> triggered. The work setup is different than the one I shared with
> you. I can make direct connections to /almost/ any SMTP server out
> there, but, paradoxically, I can't send mail to my coworkers by coming
> back in to our own SMTP server as pointed to in the public MX
> records. So, for internal mail, I use a corporate server as a "smart
> host", but for external mail I use the dnslookup driver to connect
> directly, and fallback on FAIL to our internal "smart host".
>
>> Oh, well *that* might be a better option.  I could get the guy who
>> administers smtp.boost-consulting.com to open a different port for
>> outgoing SMTP so I can send email that way.
>
> That will work in environments that block port 25, and that do /not/
> block all ports besides, say, HTTP and HTTPS. Panix runs on port
> 2525¹. I have yet to find that port blocked anywhere I use my computer.

Cool, telnet works from here.  I'll try sending you this message on
that port.

220 mailspool3.panix.com ESMTP Postfix
EHLO I9300.boost-consulting.com
250-mailspool3.panix.com
250-PIPELINING
250-SIZE 27525120
250-VRFY
250-ETRN
250-STARTTLS
250-AUTH PLAIN LOGIN
250 8BITMIME
MAIL FROM:<dave@boost-consulting.com> SIZE=5781
250 Ok
RCPT TO:<dave@boost-consulting.com>
554 <dave@boost-consulting.com>: Recipient address rejected: Access denied
QUIT
221 Bye

Heh, that was my Bcc: to myself.  I guess it won't let me send to
anyone outside Panix unless I can login there?

>> Then I wouldn't need exim at all, would I?
>
> I would still recommend running it. It solves problems that your MUA
> alone doesn't solve. You started out this inquiry looking for
> asynchronous sending behavior from Gnus, and getting that extra SMTP
> port opened won't grant you that behavior. 

Yeah, but if it's responsive enough, I don't care much.  What am I
missing?

> It will make configuring exim to fit your roaming scenario easier.

>> In fact, I could probably test this by going through smtp.panix.com
>> if you tell me what port you're using.
>
> It's mail.panix.com on port 2525, but you'll need to authenticate if
> you're not coming in through a Panix connection.

Hum, you mean I'd need a Panix username and password?

> [...]
>
>> Maybe the enclosed will help.
>
> Oh, I see they changed the "+ for DEFER or FAIL" to "&".

Yah.

> It looks to me as though your ISP is blocking port 25 traffic, 

Unless it goes to their server, yes.

> so it doesn't make sense to even try using the dnslookup router when
> you're stuck behind this connection.

I'm not always stuck there.  When I roam, won't I want that in effect?

> The "smart host" one is a short-circuit pessimistic version of your
> dnslookup+fallback: Don't even bother trying to connect directly,
> and just send it out through smtp.rcn.com.

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com