Linode Forum

[geekinthesticks]

I have been running my own mail server for several years with almost no problems sending mail. However, there is one person who has a btinternet.com address who can't receive mail from me. I have checked my server logs and I can see their smtp server accepting the email without any errors, but he never receives it. He has checked his spam folder, but he doesn't receive the email and I don't get any errors at my end.

I am about to set up a mailing list where several members have a btinternet.com address. I want to try and find out if the probem is that my email is being black listed.

I am using postfix to send email wit the following settings:

myhostname = li40-130.members.linode.com

mydestination = localhost, li40-130.members.linode.com, localhost.li40-130.members.linode.com

My domains have the following spf rrecord:

v=spf1 ip4:109.74.196.44/24 mx ?all

[obs]

Check ww.spamhaus.org that's a reasonably common black list, however the only real way to find out if btinternet have you blacklisted is to ask them.

[AgentOfPork]

A site like MXToolbox can run a check again many commonly used blacklists, but because there are so many lists, no one can cover all of them. And as obs said, the only way to know if an individual ISP has you blacklisted is to ask them. Good luck. I know working with Verizon could sometimes be a real pain. And that was when I worked for them! :lol:

[Stever]

geekinthesticks wrote: v=spf1 ip4:109.74.196.44/24 mx ?all
Your linode isn't in that ip4 range, do your domains all use this linode as their MX?

[otherbbs]

Also your linode IP reverse PTR is set to a domain that does not exist.

--
Travis

[hybinet]

geekinthesticks wrote: v=spf1 ip4:109.74.196.44/24 mx ?all
In addition to issues that others have pointed out, it's a bit odd to put an entire /24 in your SPF record. There could be hundreds of other people in that subnet, and you never know which of them will get their email script hacked one day.

"?all" does nothing. A useful SPF record should end with "~all" (safer) or "-all" (more risky).

If you also host your domain on the same Linode, the easiest way to write a valid SPF is "a mx ~all".

[geekinthesticks]

Thanks for all the helpful replies. To summarize:

As far as I can tell I am not listed in any blacklists.

I should alter my spf record to look something like:
109.74.196.44/32 v=spf1 mx ip4:109.74.196.44/32 ~all

My rDNS now resolves to mail.manor-farm.org, which is a valid domain. However, it's not the domain that I'll be using for lists.

[topcoder]

Quote: 109.74.196.44/32 v=spf1 mx ip4:109.74.196.44/32 ~all

It should be something like

v=spf1 mx a include:linode.com ~all

Just use an SPF Wizard like this one Unlock The Inbox SPF Wizard

After you get everything set up just send an email to "mailtest@unlocktheinbox.com" it will auto-respond and let you know if you got everything set up right.

[Stever]

topcoder wrote: It should be something like

v=spf1 mx a include:linode.com ~all
No, it shouldn't. Including linode.com would only make sense if linode provided an outgoing smtp relay, which they don't.

[geekinthesticks]

Thanks for the link to unlockthebox.com. However, I am obviously doing something wrong, as I can't get it to generate an SPF which it considers valid.

For example there is something wrong with the following:

Code:
v=spf1 a mx mx:mail.manor-farm.org mx: ip4:109.74.196.44 ~all

mail.manor-farm has an MX record. The headers of the message show:

Code: From li40-130.members.linode.com (mail.manor-farm.org [109.74.196.44]) by unlocktheinbox.com with SMTP; Thu, 2 Feb 2012 09:48:23 -0500
received   from [192.168.0.183] (unknown [217.146.125.41]) (Authenticated sender: ian@wilkesley.net) by li40-130.members.linode.com (Postfix) with ESMTPSA id B57F93087E3 for <mailtest@unlocktheinbox.com>; Thu, 2 Feb 2012 14:48:22 +0000 (GMT)

[hybinet]

geekinthesticks wrote: For example there is something wrong with the following:

Code:
v=spf1 a mx mx:mail.manor-farm.org mx: ip4:109.74.196.44 ~all

The dangling "mx:" is probably responsible for the error.

[Stever]

geekinthesticks wrote: Code:
v=spf1 a mx mx:mail.manor-farm.org mx: ip4:109.74.196.44 ~all

mail.manor-farm has an MX record.

Code: $ dig +short -t mx mail.manor-farm.org
$ dig +short -t mx manor-farm.org
10 mail.manor-farm.org.

There is no MX for mail.manor-farm.org, but there is one for manor-farm.org.

I think you are getting yourself all wrapped up in specifying the same IP in as many different ways as you can think of. The SPF record needs only one entry unless you are actually sending mail from multiple hosts. If you are sending all the mail from the same server, then just pick one method of specifying it's IP address. There is no benefit to specifying a, mx, and ip4 mechanisms if they ultimately all resolve to the same IP.

My standard SPF for a domain that I completely control is Code: v=spf1 mx -all
But don't use the -all unless you are absolutely certain you know what it means.

[Stever]

Also, mail.manor-farm.org != li40-130.members.linode.com
Code: $ dig +short li40-130.members.linode.com
72.14.178.130
$ dig +short  mail.manor-farm.org
109.74.196.44
$ dig +short -x 72.14.178.130
li40-130.members.linode.com.
$ dig +short -x 109.74.196.44
mail.manor-farm.org.

[topcoder]

Yeah I keep mine simple too I use..

Quote: v=spf1 a mx ~all