Gentoo Archives: gentoo-user

From: Grant <emailgrant@×××××.com>
To: Gentoo mailing list <gentoo-user@l.g.o>
Subject: Re: [gentoo-user] ssmtp alternatives: msmtp vs. dma
Date: Sat, 08 Dec 2012 02:07:10
Message-Id: CAN0CFw3M-Ydd2k2CJ+Yr6R8HURAtFpOs3qfu9i9+YKvMxH-Usg@mail.gmail.com
In Reply to: Re: [gentoo-user] ssmtp alternatives: msmtp vs. dma by Michael Orlitzky
1 > >> If you're worried about either of those scenarios, set up a separate
2 > >> account for your email alerts.
3 > >
4 > > I like the separate account idea. Any tips on locking it down? Maybe
5 > > that account on the mail server should somehow only be allowed to
6 > > deliver to a single email address (mine)? Would it need a shell
7 > > account? Certainly not allowed in sshd_config.
8 > >
9 >
10 > It depends on how you're authenticating. We've got our users in
11 > Postgres, and postfix uses Dovevot's SASL backend to auth. That way a
12 > "user" is just an email address/password combination and can't do
13 > anything except send/receive mail.
14 >
15 > The general defense against hacked user accounts is to do rate-limiting
16 > on the MTA with something like postfwd, and at least notify postmaster
17 > if someone begins sending hundreds of messages. That way if a user gets
18 > hacked, you find out about it and can disable them.
19 >
20 > In this case I wouldn't even worry about it. If someone can log on to
21 > your server and read the msmtp config, you've already got a big problem.
22 > The real benefit to using a separate account is that if that does
23 > happen, they can't see Grant's personal email password (which is
24 > essentially the keys to the kingdom).
25
26 I was planning on having the alerts sent from each system via my privileged
27 account on the mail server which means storing that password in the msmtp
28 config file on each system. If I instead set up a separate account for
29 alerts and lock that account down so it can only send email to my own
30 address, I can flaunt that password around all I want because it can only
31 be used to send email to me, correct?
32
33 By the way, is it considered safe to use my own privileged account on the
34 mail server to send mail from a good local mail client if I use SSL/TLS in
35 transmission?
36
37 > Another thing you might consider is getting added to the feedback loops
38 > of some major providers. When one of our users gets hacked, I find out
39 > quickly because AOL sends me a copy of every message that they get from
40 > us which is marked as junk. This is a Good Idea anyway, and mitigates
41 > the stolen-password problem in that unlikely event.
42
43 That sounds like a really good idea. Is there an industry-standard term I
44 could use in a search to figure out how to get the providers (Google,
45 Yahoo, AOL?) to set me up this way?
46
47 - Grant