How do i fix my reputation with hotmail? "Rate limited due to IP reputation"

[iamnothere1]

Dear members, recently every mail sent to hotmail is being put into queue, basically being blocked, not received by hotmail.
The reason is:

Jul 6 12:29:47 edgeserver postfix/qmgr[2128414]: 6ADC2E20B6: from=<xxx@xxx>, size=2914, nrcpt=1 (queue active)
Jul 6 12:29:48 edgeserver postfix/smtp[2591186]: 6ADC2E20B6: host hotmail-com.olc.protection.outlook.com[104.47.18.161] said: 451 4.7.650 The mail server [OUR IP] has been temporarily rate limited due to IP reputation. For e-mail delivery information, see https://postmaster.live.com (S775) [AM7EUR06FT042.eop-eur06.prod.protection.outlook.com 2023-07-06T10:29:48.157Z 08DB7D761429A9D0] (in reply to MAIL FROM command)
Jul 6 12:29:48 edgeserver postfix/smtp[2591186]: 6ADC2E20B6: lost connection with hotmail-com.olc.protection.outlook.com[104.47.18.161] while sending RCPT TO

Basically our reputation with hotmail is bad, and all the mails sent to them are being put in a queue.

I think the reason this is happening is because we are sending a lot of mails to hotmail now, because we need to, but these are not spam mails, just a higher volume than usual.
We contacted support, they say we are not eligable for delisting yet.
Some of the websites from Outlook for delisting are not even working properly.
We have SPF and DKIM enabled, and we have Proxmox MG as Gateway, with subscription.
Error in question is: SMTP 451

Does anyone else have any experience with hotmail blocking their mails, if so, how did you solve this?
Is there any way we can fix our repitation?

Just to add, gmail and every other mail service is receiving our mails properly, its just hotmail
Thanks

 

[Trulli]

Hotmail is very restrictive on accepting email from "bad sources" (interestingly O365 not so much..); Especially you are affected if you are using a rented server from one of the bigger providers, the likeyhood that their whole or significant parts of their network is on hotmails blacklist is high, as there are spammers "in your neighboorhood". Dont worry i have seen worse, either hotmail accepting the mail but never actually delivering (blackhole) or refusing it outright (and not throttling you). We gave up years ago, and use another provider to pipe emails through towards hotmail domains. You can contact your hosting provider to try to improve this situation, but if you are in a "shared" environment, the likelyhood is high to always end up again with the same issue.

 

[smileluo]

You can contact microsoft for investigating your IP,basiclly you can check your IP at mxtools to see the raputation or buy smart host and etc.

 

[iamnothere1]

Thanks for the reply guys,
We are not in a shared environment, we have one public IP address that provider gave to us which we use for Proxmox,
We are not on any Blacklist, we checked on MXtoolbox, we also contacted Microsoft support but they are not of a much help. basically just said we are not eligable for delist, or something like that.
This happened since we started sending a big amount of mails towards hotmail, so i guess that made them block us.
We decided to wait, and not send any mails to hotmail, and see if that helps the problem, we will also send another support mail to Microsoft in few days if the situation doesn't get better