Those email servers that are doing a DNSBL lookup in realtime may sometimes see a DNS timeout or similar. It can happen, reguests don't get answered before the time-out period so in that case the email software will usually ignore the job and continue as if the DNSBL had responded "not listed". The effect of these time-outs is that spam can be either passed for delivery and / or not marked with an X-Header. In short, inboxes see more spam.
Running a local copy of a DNSBL avoids this problem as the lookup requests are entirely on your own network, or even on the same server. That would ensure the continuity of access to the DNSBL data and keep inboxes free of spam. Maintaining local copies of databases, regardless of whether their data is changing frequently or not, can be tedious but not with RSYNC.
Rsync is a nice routine for downloading only changed data from a database host. Most if not all the DNSBL operators offer RSync and have instructions on their website for how to use it to obtain their data. L2.APEWS.ORG is also available by rsync. It is worth adding that many DNSBL data and services are provided totally free to all users.
I won't get into the installation and configuration of Rsync here, there are other places on the internet that adequately explain that. Unix and Linux users have probably already come across it, and Microsoft Windows users could install e.g. Cygwin. Check for compatibility with your particular operating system etc.
Hello, we have received notice that our email domain server has been blacklisted by l2.apews.org. We are a small/medium food co-op in northern Wisconsin, and our only mailing list contains the email addresses that were given to us by our co-op members. What can we do to remedy this situation? Our emails are being rejected by businesses with whom we do business, which is concerning to us. Any advice would be appreciated. You may reach me at outreach (at) cheqfood (dot) coop
ReplyDeleteThank you.
The L2 blacklist contains only IP addresses and you can easily check a listing yourself by visiting the www.apews.org website. If it is listed in error then publishing the fact here is a good start. We can not tell exactly which IP address you are talking about here since you could be using different MX servers for inbound and outbound emails which may not be apparent from a WHOIS lookup.
ReplyDeleteYou say that your mailing list was given to you and it sounds like you trust the source being fellow members of the coop, however you should be aware that for many email recipients, the issue of spam is one of consent, not content. The expectation is that a sender has express permission but that permission can not be transferred to 3rd parties.
The quickest solution to your immediate problem is to ask that your email server IP address be whitelisted by the intended recipients. Not always the case but the idea is that email server Administrators can be emailed using their role account email address (typically postmaster@...) for the domain or domains that they manage in order to ask for a whitelisting. If that is approved then your server would be allowed to connect and deliver it's email without reference to the L2/Apews/org listing.
Another consideration is that your mailing list is contaminated with one or more email addresses that does not have permission granted. I would suggest verifying the mailing list with your fellow members in case it contains one or more errors. If the mailing list is e.g. all the coop members, then it shouldn't take too long to check.
It isn't known where Apews.org get their data but one has to assume that it is based on fact. Do you share your email server referred to above with anyone else? Could that server have emitted spam, not by you or your members, but by a 3rd party or virus? If spam has been detected from that email server's IP address or even an IP address close by, then the IP address or group of IP addresses could have been assessed as high risk for spam.
Consider also the reputation of the network from where your email server gets it's IP address. If the ISP or hosting firm is a bad judge of client or doesn't get rid of spammers on his network then it is a badly managed network with a correspondingly low reputation. The fact that Apews identifies 99+% of spam for our users with almost no errors is a fairly good indicator that unlisted IP addresses are trustworthy, i.e. run by responsive and professional Administrators.
HTH, see also the post on whitelists.