Can receive emails, but not send

Everly

Hello, I can receive emails, but I cannot send any. When I try sending an email, it returns with the following message:

I saw another post on here that asked if they could telnet the IP that timed out, but the person didn’t respond. I tried on my computer and it works, but on the server it also times out. I can ping the server, though. Any ideas? Thanks.

If it helps, my mailcow instance is hosted at mail.everly.page.

And here is my cloudflare dns for mailcow stuff

D4niel

Everly I tried on my computer and it works, but on the server it also times out

If it doesn’t work from your server it’s probably some kind of firewall issue. Either you’ve configured your outgoing rules wrong or your hoster/ISP is blocking port 25 to prevent abuse. For example Hetzner Cloud servers by default block port 25 and 465 to protect from spammers. You can request to get the ports unblocked from their support.

Everly

D4niel I’ve disabled the firewall to see if that’s an issue. I also have another instance of mailcow running on another server from the same provider and it works fine. I could contact them to see but I don’t think that would be the issue.

luchris

Telnet from your pc to your server on port 25 and check if it timeout too

Everly

luchris

What is the rest of the message after

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

               The mail system

Everly

luchris Like what are the email attachments?

luchris

Sorry, i got confused. Can you send an email from this box to maybe a gmail or hotmail address and see if it gets delivered

Everly

luchris I’ve tried doing that and it gives me the same message

luchris

I got a feeling your IP is blacklisted.

Check it against the rbl https://multirbl.valli.org/lookup/

Also can you nslookup your IP to see if it has a rDNS?

luchris

You mentioned that you have another mailcow box correct? Can you try sending a test to the working box. Then check the postfix and rspamd logs to find out what is wrong?

If you dont even see the connection, then most probably your provider is blocking outgoing on port 25, but allows incoming on the same port