First of all, I’m still learning and pretty inexperienced, sorry for stupid mistakes.
I got my mailcow server set up and running. Receiving mails works and sending mails to y mailbox on my own server works too, but mails sent to other providers mailboxes like my private one seem to be blocked.
For this I need to mention that I run mailcow on my homeserver, using a domain with DDNS for connection. All ports are opened properly. My provider is “wilhelm,tel” (only active in north germany) and my router is an AVM Fritzbox.
When going to the Queue Manager I see my outgoing emails wit hthe queue status deferred, in the recipients field I see some “error message”. It tells me that the mail provider I sent the email to refused to talk to me, this is the message: refused to talk to me: 554-web.de (mxweb105) Nemesis ESMTP Service not available 554-No SMTP service 554-IP address is block listed. 554
It also gives me a link supposed to explain it, that just tells me “554 Nemesis ESMTP Service not available No SMTP service IP address is block listed.”
That site also links to check.spamhaus.org, seemingly some provider that check IPs and domains for spam and provides that list to mail providers to block them. Checking my IP adress tells me there is one listing, I’ll just copy the part that seems important:
Outbound Email policy of Wilhelm.Tel GmbH for this IP range
It is the policy of Wilhelm.Tel GmbH that unauthenticated email sent from this IP address should be sent out only via the designated outbound mail server allocated to Wilhelm.Tel GmbH customers. To find the hostname of the correct mail server to use, customers should consult the original signup documentation or contact Wilhelm.Tel GmbH Technical Support.
Google searches sadly did not lead to any results. What exactly does this mean? Does my ISP just block all mailserver on customer IPs? Sounds like they are selling their own mail service. Is there any way around this?
The site also mentions “If the IP address you are using is on PBL, you can still send email if you are using SMTP auth.”, what exactly is that and is it an option for me? If yes, what do I need to do?
Any help is much appreciated if you’ve read until now. Thanks.