Hello,
I have 500+ Outgoing Mails in the queue (exchange 2010)
Customer is doing much email marketing.
He is sending his emails directly without smarthost.
This configuration is working well since many years now.
Today Customer said that many non-delivery-mails came back.
He said he sends 5000 outgoing mails per Week and only<tcxspan #="" 172.16.20.19:5001="" call?phone="5001000"" https:="" tcxhref="https://172.16.20.19:5001/webclient/#/call?phone=5001000" title="Call<tcxspan tcxhref=" webclient="">500-1000 </tcxspan>with came back usually with error
The Blacklist Check of mxtoolbox.com said: listed at SORBs.
Sorbs Support confirmed delisting of the IP. Sorbs said: clear list the receiverlist e.g. of non-existant domains.
I am sure that there isn´t a spambot in our local network. (beacuse sorbs showed me the header they trapped and it was a newsletter)
At the Moment I see 251 Entries with
451 4.4.0 Primary target IP Adress responded with: "421. 4.2.1 Unable to connect. Attempted failover to alternative host...
and
451 4.4.0 DNS query failed