Exim configuration: Live Mail (Hotmail) deliverability issues

-- This question is directed to people with Exim and mass mail experience --

Greetings,

I am the developer of a large job directory site. We send about 150.000 mails a day. We are currently experiencing massive deliverability issues with only Microsoft Live Mail. Let's summarize what we did:
- SPF records
- Reverse DNS
- Junk Mail Reporting Program (Low complaint rate)
- Verify HELO records and other settings
- Extensive contact with Live Mail support
- Add another server with 2 IPs

We use queueing in our web application; we send 120 mails every minute. Another site we run that uses the same mail IP doesn't use queueing yet; it pumps out all mail immedatately. This might cause our reputation problems.

I think throttling/rate-limiting ALL outgoing mails to Hotmail domains in Exim (Live etc. too) might help, though I have no idea how this works and what settings would be recommended. I hope someone went through this already and has a solid Exim configuration for mass mailing 'Live Mail' people.

Thanks in advance!

JW

421 RP-001 The mail server IP connecting to Windows Live Hotmail server has exceeded the rate limit allowed. Reason for rate limitation is related to IP/domain reputation problems. If you are not an email/network admin please contact your E-mail/Internet Service Provider for help. Email/network admins, please visit http://postmaster.live.com for email delivery information and support
 
New server with other IP address gives this error (but also in SPF etc):
 
550 SC-001 Mail rejected by Windows Live Hotmail for policy reasons. Reasons for rejection may be related to content with spam-like characteristics or IP/domain reputation problems. If you are not an email/network admin please contact your E-mail/Internet Service Provider for help. Email/network admins, please visit http://postmaster.live.com for email delivery information and support 
 
(Note: we have a low complaint rate)

Select allOpen in new window