Bug#869480: Support multiple smarthosts (gmail support)

[Osamu Aoki]

Package: exim4-config
Version: 4.89-2.1
Severity: wishlist
Tags: patch

Hi,

Current smarthost set-up can use only one smarthost.  These days, that
will cause outgoing mail with unmatched From: _From ... may get flagged
as spam.  So use of the account specific smarthost is getting important.

For example, gmail accounts, it is best to use the pertinent account to
use message submission port at 587 with STARTTLS.  (Otherwise, from:
address are overwritten.)

To pick smarthost, I think ${address:$h_from:} is better than
$sender_address.  So I added few lines for smarthost setting to realize
this as attached patch.This approach should make outgoing mails to be
more robust against spam filters.

(I am also trying to add a remote shell account support as an extra
experimental feature.  This should be good for people.debian.org etc..)

Yes, this sounds like my old closed bug:  https://bugs.debian.org/656841
(Well it was more of SSMTP.  Also code example was buggy.)

The https://wiki.debian.org/GmailAndExim4 is outdated (I agree that
localdomain in HELO/EHLO line may be bad idea.)

But since then, mail situation get more restrictive with dkim, spf, and
dmarc, we really need to use sender matched SMTP servers.

So this needs to be done properly.  I was inspired by few similar
attempts.  Here are my comments on them:

https://medium.com/@krala/exim4-and-multiple-gmail-accounts-c8fae2ac60a3
 * No need to use ${lc:...} since lsearch is case insensitive
 * Should use ${address:$h_from:} instead of $sender_address
 * No need to have separate CONFDIR/gmail-accounts
 * No need to limit to gmail

https://gist.github.com/kanru/3368424
 * Why only one account per domain?
 * Why new config file CONFDIR/smarthosts ?

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=750122
 * Mark is right on technical side that this kind of config chokes
   performance.  But when using mutt to read and reply multiple mail
   accounts on your work station, that is negligible.  Automatically
   using right SMTP relay gives huge advantage against spam filter these
   days.

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=541473
 * This wishlist is addressed by this patch.

Anyway, the current results are attached.  I may update these patches in:

  https://github.com/osamuaoki/exim4-debian-pkg

I hope this helps.

Osamu




-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-Local-modified-package-to-support-the-new-account-ba.patch
Type: text/x-diff
Size: 882 bytes
Desc: not available
URL: <http://lists.alioth.debian.org/pipermail/pkg-exim4-maintainers/attachments/20170724/0f5d727f/attachment.patch>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0002-Refactor-around-PASSWDLINE.patch
Type: text/x-diff
Size: 3608 bytes
Desc: not available
URL: <http://lists.alioth.debian.org/pipermail/pkg-exim4-maintainers/attachments/20170724/0f5d727f/attachment-0001.patch>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0003-Message-submission-to-each-mail-account.patch
Type: text/x-diff
Size: 4567 bytes
Desc: not available
URL: <http://lists.alioth.debian.org/pipermail/pkg-exim4-maintainers/attachments/20170724/0f5d727f/attachment-0002.patch>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0004-Experimental-ssh-sendmail-support.patch
Type: text/x-diff
Size: 3157 bytes
Desc: not available
URL: <http://lists.alioth.debian.org/pipermail/pkg-exim4-maintainers/attachments/20170724/0f5d727f/attachment-0003.patch>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0005-Update-passwd.client-doc.patch
Type: text/x-diff
Size: 2495 bytes
Desc: not available
URL: <http://lists.alioth.debian.org/pipermail/pkg-exim4-maintainers/attachments/20170724/0f5d727f/attachment-0004.patch>