Hello, My problem is that i cannot receive or send emails. My server isn't blacklisted, i checked it here: mxtoolbox. com/blacklists.aspx I have spoken with the provider and he blocks the port 25. i have also tried this: telnet smtp.gmail.com 587 and it connects so i can use the port 587. But i want your help configuring my system. I use horde but i havent any problem using the default SquirrelMail app. Extra info: Mail - Log > pastebin{.}com/SFwsv0Wn Thanks a lot
Email is sent and received between servers on port 25, so you wouldn't be able to send or receive even if you weren't blacklisted.
You can send mail through an external server/service on port 587, but you cannot receive mail there, all external servers will use port 25. You simply cannot run an smtp server without port 25 open. You could put up a secondary server somewhere else that does allow port 25 the accept mail and forward to you on 587; or you could buy a service from somewhere which does a similar thing. Or either convince your provider to open port 25, or move your server to another network segment (colocated or vps or something) where it isn't blocked.
Today i talked with my provider and he said that. I can receive emails from port 25 but i cant send. For sendind emails i must use the 587/submission port. So what i have to do now? Thanks
If you can not send mails over port 25, you must use an external server that accepts your mails on port 587.
i reinstalled ISPConfig in a fresh debian system. And configured it carefully. Now i can receive emails. But i dont know how to configure my server to use external server to send emails EDIT: I used these 2 tutorials and now i can send also emails via port 587 -https://www.linode.com/docs/email/postfix/configure-postfix-to-send-mail-using-gmail-and-google-apps-on-debian-or-ubuntu -https://easyengine.io/tutorials/linux/ubuntu-postfix-gmail-smtp/
The tutorials do not configure your server to send mails using port 587. You just send your mails using your gmail-account. That's what i wrote in #6.
You can only send trough a relay server when port 25 is blocked, there are no other options then relaying trough another server or getting a real server in a datacenter where port 25 is not blocked.
