On Tue, Oct 26, 2010 at 10:25:32PM +0200, Rok Poto??nik wrote:
> On 26.10.2010 22:08, Jeroen Geilman wrote:
>> Then you're probably accepting way too much mail that you shouldn't, as
>> the other guy said.
>> Even with volumes exceeding 100K per day, I don't have deferred messages.
>
> ISP mail servers usually accept a large number of messages that most
> company's mail servers reject (e.g. only accept only email sent from the
> hosted domain). Unfortunately we can only limit the email till one point,
> after that we must somehow work around the issues...
Arm's-length backup MX hosts, that don't know the target domain's
recipient list and don't offer the same anti-spam defense do more harm
than good. If you are an ISP that offers backup-MX services, you should
work with your clients to obtain and maintain valid recipient lists, or
work with the client to discontinue the backup MX service.
--
Viktor.
