Dear list
SWITCH is organising the 3rd Swiss Web Security Day, together with Swico and SISA.
If you are interested in Web Security join us on October 30th in Bern.
Registration and more Information about the event is available here:
https://www.eventbrite.de/e/swiss-web-security-day-2019-tickets-65098353929
Hope to see you in Bern
Michael
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Michael Hausding,
Competence Lead DNS & Domain Abuse
SWITCH-CERT
Werdstrasse 2, P.O. Box, 8021 Zurich, Switzerland
phone +41 44 268 15 77, incident phone +41 44 268 15 40
michael.hausding(a)switch.ch
http://securityblog.switch.ch
We currently experience mail delivery issues with bluewin.ch recipients.
> 452 4.1.1 <REDACTED(a)bluewin.ch> requested action aborted: try again later
we have tons of those message since this morning. From time to time mail
can be delivered. Not have them before today
Anyone seeing similar issues with bluewin? Or anyone from bluewin
reading this list (can contact me offlist if desired)?
Thanks for any help with this issue
tobi
Hi All
We are experiencing problems delivering mails for domains having their MX record set to mx-eu.mail.am0.yahoodns.net (for example yahoo.it, yahoo.de, yahoo.co.uk). So far we have figured out that Yahoo’s DNS servers send different responses. Depending on the DNS response we are able to establish SMTP connections. Below example shows 2 servers from their DNS that seems to accept SMTP connections:
[root@x1:~] # dig a mx-eu.mail.am0.yahoodns.net @yf2.yahoo.com +short
188.125.72.73
188.125.72.74
[root@x1:~] # telnet 188.125.72.73 25
Trying 188.125.72.73...
Connected to mtaproxy1.free.mail.vip.ir2.yahoo.com.
[root@x1:~] # telnet 188.125.72.74 25
Trying 188.125.72.74...
Connected to mtaproxy2.free.mail.vip.ir2.yahoo.com.
On the other hand we sometimes get other replies from the “same” (the id.server chaos record tell’s us it’s a different one) DNS server with different A records that do not accept SMTP connections:
[root@x1:~] # dig a mx-eu.mail.am0.yahoodns.net @yf2.yahoo.com +short
188.125.73.87
212.82.101.46
[root@x1:~] # telnet 188.125.73.87 25
Trying 188.125.73.87...
telnet: connect to address 188.125.73.87: Operation timed out
telnet: Unable to connect to remote host
[root@x1:~] # telnet 212.82.101.46 25
Trying 212.82.101.46...
telnet: connect to address 212.82.101.46: Operation timed out
telnet: Unable to connect to remote host
We have so far confirmed this behaviour from different AS (Hetzer, OVH). Does anybody else experiencing the same behaviour?
We have tried to contact their postmaster address and few others we found on the internet. Unfortunately so far no one was really able to help us. The Yahoo Small Business Phone Number that has been posted on this list back in October 2009 seems no longer to be in operations too. Therefore if you know how to get in touch with their technical staff that would be much appreciated.
Best Regards
Dominic Schlegel
