David Michard wrote:
Hello,
I know this question has been discussed on this list* but no suitable
solution was provided for our SMTP server settings.
A patch** is published but reports on this list say that it does not work.
I am responsible for a medium sized mailing-list, through which one
email is sent per day to roughly 600 000 subscribers. Since our
mailing list is growing, we are having more and more problems with
very conservative SMTP servers enforcing a low number of simultaneous
connections from a single IP address. Our subscribers wish to receive
their email as soon as possible so delaying the email for a few hours
is not an option.
I was thinking of allocating 4 IP aliases for our SMTP server so that
connections would appear to come from different servers. The goal is
not to flood*** the target server as our own postfix server has its
own limit to the number of simultaneous active connections, set to 30
connections.
The application uses the "sendmail" binary to send email, and not SMTP.
One email is sent per subscriber and signed with dkimproxy plugged
onto the "pickup" daemon.
Each email is always sent from the same nore...@mydomain.org address.
Is it possible to tell postfix to randomly select an IP address, and
associated hostname (as many smtp servers perform RDNS lookups and
compare it to the HELO/EHLO greeting) when sending an email ?
That would be very helpful.
Regards,
David.
(*) http://www.mail-archive.com/postfix-users@postfix.org/msg18400.html
& http://www.mailinglistarchive.com/postfix-users@postfix.org/msg57399.html
(**) http://denixsolutions.com/Scripts/Postfix-Multiple-Interfaces-Patch
(***) At this stage I feel it is necessary to stress that the
mailing-list is not for profit and that we take every step to make
sure that subscribers who change their mind are unsubscribed as soon
as possible. We use confirmed opt-in (aka "double opt-in") for
subscription, simplified unsubscription, every RFC compliant headers
required for bulk emailing, VERP, SPF, DKIM, complaint feedback loop
with ARF with most providers etc in order to maintain a high
deliverability ratio. I am not willing to give the name of the
organisation so you will have to take my word for it.
We do this by using multiple postfix configs/queues as in postfix{1-5}
with each binding to its own ip.
Thanks,
Randy Ramsdell
