Emails being blocked

email, spam, blocked

[brancook]

We have been having alot of issues with our emails getting kicked back from our server with the message: "Sorry, I wasn't able to establish an SMTP connection.(#4.4.1) I'm not going to try again; this message has been in the queue too long ... "

We started having the issue when we were on a shared server, I've since switched to our own VPS which has improved the issue a bit but we still occasionally get blocked.

I've had our host open up a new port, that didn't seem to help. Is there any way for me to check to see what is going on and to find our exactly why we are being blocked? I'm starting to get really desperate. Our IP address isn't blacklisted, I tried to email the host that is blocking us but I can't get through to them either because the email just sits in the mail queue on the server.

Any advice would be greatly appreciated.

Thanks
Brandon

[LifeinAsia]

If you can't reach them by phone, try e-mailing from a different server (even from free mail services like Yahoo and Hotmail).

[brancook]

It's not just one domain that we are being blocked by. I did email them from my home email this evening just to try to make some progress.

[LifeinAsia]

You may want to try additional or different DNS servers that your mail server uses. I seem to remember that we had a flood of mail problems some months back that was got fixed by changing the DNS entries.

[brancook]

Open relay looks as if it could be the problem. Some host will block emails if they have open relay on and use the SMTP connection. Should I close the open relay?

[LifeinAsia]

Should I close the open relay?

Most definitely!

[brancook]

Problem, I was told by our host if I do this then I can't use Microsoft Outlook. Is that true?

[mcavic]

If your relay is closed, then everyone who sends mail through your server from a program like Outlook needs to be authenticated, either by their IP address, or with a username and password. The user/password support can be tricky to set up. If you have a Web Mail system, or your host does, then it would probably still work regardless.

[brancook]

We do have a web mail system we use Horde. But I was told by my host that Outlook would not work. Did they tell me that just so I would pay them to set up the rDNS or PTR.

[mcavic]

It's true that Outlook and programs like it can't send mail through a closed relay on a hosted server, without authentication. And it's very possible that the host doesn't know how to set up the authentication.

By the way, all mail servers should have a reverse DNS that points to the correct name of the server. I can't say that it's absolutely necessary, but it's definitely desirable for spam filtering.

[brancook]

Is that something to look for in a host? Should I ask them "Can you set up a closed relay with authentication."?

So using Microsoft Outlook really opens the world to spam and open relay abuse?

[wheel]

So using Microsoft Outlook really opens the world to spam and open relay abuse?

Hey, you're preaching to the converted here in the linux forums. MS Outlook also contributes to world hunger and acne.

No, what they're saying is that it just requires some specialized setup to make it work with your mailserver. So you have to find someone that knows or is willing to do that setup. The alternative of running an open relay should not be an alternative. I wasn't even aware that people did that.

[brancook]

"I wasn't even aware that people did that."

Are you referring to open relay? It was open by default when I switched over to the VPS. So should I really pursue closing that even though my host has told me it isn't really an issue?

[brancook]

When I look at the headers of the emails that aren't being delivered that are sitting on the server, the seconded Received line where it states from then an IP address, it lists the IP address of my computer not the IP address of the VPS server. Do I need to upload spf records to the dns saying that my computers IP is allowed to send mail through the vps?

[brancook]

So I walk in this morning and I'm told that qmail has been set to the defaults and they have closed open relay. My microsoft outlook seems to be working. Does that mean they have set up authentication as well.

I had been asking them about the open relay setting and they just kind of brushed me off as that not being the option.

[adrianTNT]

You may want to try additional or different DNS servers that your mail server uses. I seem to remember that we had a flood of mail problems some months back that was got fixed by changing the DNS entries.

I recommend this too, I had this issues few times with my dedicated servers. I cannot remember the file name to be edited, there is a file that contains the DNS names (usually 2 lines), and the DNS mentioned there ware offline, that caused the email connection to fail and emails got stuck in queue.