DKIM support

[david]

Hello,

My mail server sends out lots of notifications regarding events that occur in my systems. Such emails, due to the massive templated mails generated, have a SPAM-ish behaviour. To avoid being marked as spam there are some actions I can take in advance like adding a SPF records to my DNS.

As far as I understand there are possibilities for marking (is this the right term?) a message using DKIM spec. I understand that a mail server either supports or not supports this feature.

Does Ability support it? If not - is there any plan to support it? If not - is there an alternative solution Ability mail server offers?

Thanks!

[rob]

I believe DKIM works similar to SSL and digitally signs mails as being genuinely from a particular domain. DomainKeys / DKIM is something we have considered adding before and is still in our list of desired updates. At present we have no planned implementation date but should it continue to grow in popularity it will of course encourage us to add this feature. Of course SPF records can help as you have done, but it is unfortunate that auto genereated mails will often struggle with the huge number of SPAM systems now in operation. Another option in the mean time may be to look for a third party add on which can add DKIM to AMS. Unfortunatly we do not know if any such software exists but a quick search on the internet may be worth your time.

[elimelight]

Hi Rob,

We have recently been experiencing a lot of problems with emails destined for BT/Yahoo users. Firstly the warning, and then the failure...

The following mail failed to be delivered...
From: steve@elimelight.co.uk
Sent: Sat, 25 Jul 2009 11:48:19 +0100
Subject: RE: Auctions
To:-
x@y.com - Rejected with: 421 4.7.1 [TS03] All messages from 217.112.91.246 will be permanently deferred; Retrying will NOT succeed. See http://postmaster.yahoo.com/421-ts03.html

Yahoo offers a Mail's Complaint Feedback Loop program, which I assume is like the hotmail one, where you can at least get some idea of which emails/domains are causing Yahoo servers to consider ours as a source of spam. The trouble is, Yahoo will not allow us to subscribe to this system. Senders who wish to participate in the Complaint Feedback Loop program are required to sign their outbound email with DomainKeys and/or DKIM, both of which are email authentication technologies that Yahoo! Mail utilizes to determine the actual sender of an email. (They do not offer feedback loops based on a sender's IP addresses or CIDR ranges.)

Reading the earlier posts in this topic, which are over a year old now, it seems AMS can't help with this, or couldn't a year ago. Has anything changed, as it is a real show-stopper if our customers emails can't get to Yahoo/BT accounts.

I need some urgent advice please as to how to get through this prolem now.

Many thanks.

Steve

[Code Crafters]

Large mail servers such as Yahoo, Hotmail and AOL block any email that originates from a dynamic or ISP assigned IP address. To get around this you can add a static route for these domains which will relay mail to them via your ISPs SMTP server (usually smtp.yourisp.com) which will be more trusted and often delivered. You can of course use relay mode to relay all your mail via your ISP but in your case - sending lots of mails - I wouldn't recommend a full relaying. We have to do this also for one of our offices which has a dynamic IP but not in another of our offices which has a static IP.

Yahoo, as you mentioned, can also block based on not supporting DKIM which is a strict policy since this is not a widely implemented feature which so far I've only known of Yahoo requiring and/or using it. As Rob said previously, this is on our (very big) to-do list of features which are implemented based on popularity. We are getting a few requests for this feature but not that many but will look at adding it at some point although I can't promise anything at this stage. There may be as Rob said an intermediate software that could relay mail from your AMS to the Internet adding a digital signature to it to get round this problem as short term fix.

[elimelight]

Hi Chris,

We have a fixed IP address, as our server is co-located in a data centre. They do not offer a shared SMTP service. We have not had a problem in the past. We have been running your mail server software for years.

So, can't reroute through any ISP! Any other suggestions would be appreciated.

Thanks.

Steve

[Code Crafters]

With a static IP you usually don't have these problems. After looking closer at the link provided with the error I can see that they have blocked your mail because they believe you are sending too much volume of mail to their server which they are assuming to be SPAM, see http://help.yahoo.com/l/us/yahoo/mail/p ... -ts03.html or below:

This error message indicates we are seeing a high volume of messages from your IP address that is a characteristic of unsolicited, bulk emails. While this is a temporary SMTP error code, we do not recommend attempting to resend your messages until you examine your subscription practices and lists, and implement changes to ensure that your messages are sent only to users who have requested it. Please visit this page to review our best practice recommendations.

If you have deployed significant changes or feel you have received this message in error, you may contact our Postmaster team by filling out this form.

This is nothing to do with AMS's operation and only to do with high email volumes which you can contact them to discuss. However, it is only a temporary error so it should eventually timeout the block on your IP and let mail back through again as long as you don't abuse by sending too much.