On 7 Mar 2012, at 15:48, Jeffrey Starin wrote:
> On 3/7/2012 10:27 AM, Warren Baker wrote:
>>
>> On Wed, Mar 7, 2012 at 3:39 PM, Jeffrey Starin <jeffrey.starin@??? <mailto:jeffrey.starin@gmail.com>> wrote:
>>
>> A little insight as to what is an external helper? Thanks.
>>
>>
>> That is a little beyond the scope of this list but something that tails the log file (a perl script as an example) and reacts when needed.
>>
>>
>> thx
>>
>> --
>> .warren
> I guess I'm asking, which presumably would be in the scope of the list, is what exim command(s) would reload a different configuration file without hiccuping.
I think this is all in the scope of the list, which is intended to assist Exim users with any problems relating to persuading Exim to behave as required. The solution probably does require more than a clever configuration file, though.
In this case, the question is how can we persuade Exim to behave intelligently with respect to previous SMTP replies from Yahoo. Specifically, certain replies from Yahoo might require us to (a) back off with delivery attempts, or (b) to use a different IP address for delivery.
Response (a) is what Yahoo are after. It might be possible to do that better with a specific line in the RETRY section of the configuration file. Section 32 of the docs might give you some ideas. For example, can configure a retry strategy based on recipient domain and return code number (sec 32.5).
Response (b) is circumventing Yahoo's anti-spam protection, and it's somewhat harder to achieve. The easy bit is setting up the smtp transport. You need to set the "interface" option, which is expanded at delivery time, so it can be looked up from a file (or ldap server, or whatever), if the recipient domain is yahoo.*, for example. The tricky bit is ensuring that the file has the right content. For that, you probably need to write a script that watches your log file and flips the content of the file when necessary.
Or, you could have an ACL that uses $run to trigger the script when it sees a Yahoo recipient, but that could be very inefficient if, well if you're sending enough mail to Yahoo that you're seeing this problem!
--
Ian Eiloart
Postmaster, University of Sussex
+44 (0) 1273 87-3148
