Hoi zäme
I have a couple of customers complaining they are unable to send emails to hotmail - typically they see rejects such as this:
550 SC-001 (BAY004-MC5F11) Unfortunately, messages from 88.198.198.124 weren't sent. Please contact your Internet service provider since part of their network is on our block list.
It doesn't affect all customers and checking our logs, it appears to have started 18/1. Prior to that we had no problems delivering outbound mails to hotmail, since then I see 149 bounces with the message above).
The customers are on dynamic ranges from Swisscom, UPC and e.g. Virgin (in the UK). Has anyone seen something similar?
Hello,
it could be that you problem is related to DMARC.
big changes are coming, big email providers like gmail,yahoo and I guess also hotmail are implemeting DMARC. Use of Strict DMARC Policies will make this big providers reject emails.
https://dmarc.org/2015/10/global-mailbox-providers-deploying-dmarc-to-protec...
Saverio
On 21/01/16 10:46, Per Jessen wrote:
Hoi zäme
I have a couple of customers complaining they are unable to send emails to hotmail - typically they see rejects such as this:
550 SC-001 (BAY004-MC5F11) Unfortunately, messages from 88.198.198.124 weren't sent. Please contact your Internet service provider since part of their network is on our block list.
It doesn't affect all customers and checking our logs, it appears to have started 18/1. Prior to that we had no problems delivering outbound mails to hotmail, since then I see 149 bounces with the message above).
The customers are on dynamic ranges from Swisscom, UPC and e.g. Virgin (in the UK). Has anyone seen something similar?
Saverio Proto wrote:
Hello,
it could be that you problem is related to DMARC.
big changes are coming, big email providers like gmail,yahoo and I guess also hotmail are implemeting DMARC. Use of Strict DMARC Policies will make this big providers reject emails.
https://dmarc.org/2015/10/global-mailbox-providers-deploying-dmarc-to-protec...
The senders have not published any DMARC entries - also, sometimes it works, sometimes it doesn't. I have just tried sending mails to "postmaster@hotmail.com" from a couple of our servers at Hetzner, same error message. Other messages go through fine. (28 today sofar).
/Per
Per Jessen wrote:
Hoi zäme
I have a couple of customers complaining they are unable to send emails to hotmail - typically they see rejects such as this:
550 SC-001 (BAY004-MC5F11) Unfortunately, messages from 88.198.198.124 weren't sent. Please contact your Internet service provider since part of their network is on our block list.
It is truly weird. Using the same sender and same path, one email to "some.user@hotmail.com" is accepted, another to "postmaster@hotmail.com" is rejected.
It is truly weird. Using the same sender and same path, one email to "some.user@hotmail.com" is accepted, another to "postmaster@hotmail.com" is rejected.
They are probably ramping up rejection rates slowly, as suggested here: https://dmarc.org/overview/
i experience this a long time (more than 3 years) all try to resolve that where without success
a workarround was to use another range in an other AS to send email to M$ system
On 21/01/2016 06:14, Saverio Proto wrote:
550 SC-001 (BAY004-MC5F11) Unfortunately, messages from 88.198.198.124 weren't sent. Please contact your Internet service provider since part of their network is on our block list.
Gregor Riepl wrote:
It is truly weird. Using the same sender and same path, one email to "some.user@hotmail.com" is accepted, another to "postmaster@hotmail.com" is rejected.
They are probably ramping up rejection rates slowly, as suggested here: https://dmarc.org/overview/
After I filed a support request with Microsoft, they got back to me fairly quickly and said one of our IP-ranges was "a candidate for mitigation". No other explanation offered. I don't see this being a dmarc issue at all, but some sort of internal M$ "reputation list".
Thanks for everyone's suggestions!
Wow at least you got a feedback, which is more than i got the last 3 years i have given up, my client know mail delivery to microsoft mailservice is not guaranted, and i recomend to convince mailpartner for a change to a more cooperative Mailprovider. if i´m able to route microsoft mail via relayhosts on IP-ranges/AS which are not blocked, but i wont spend much time anymore in timeconsuming workarrounds.
Roger
On 25/01/2016 05:52, Per Jessen wrote:
Gregor Riepl wrote:
It is truly weird. Using the same sender and same path, one email to "some.user@hotmail.com" is accepted, another to "postmaster@hotmail.com" is rejected.
They are probably ramping up rejection rates slowly, as suggested here: https://dmarc.org/overview/
After I filed a support request with Microsoft, they got back to me fairly quickly and said one of our IP-ranges was "a candidate for mitigation". No other explanation offered. I don't see this being a dmarc issue at all, but some sort of internal M$ "reputation list".
Thanks for everyone's suggestions!
-
Gregor Riepl -
Per Jessen -
Roger -
Saverio Proto