3.42. Help!!! All messages from my list are being rejected by AOL (or hotmail, or Yahoo! or Google Gmail/googlemail, etc...) as spam, or being silently thrown away!
Some large ISPs and some medium and smaller ones too have a tendency to declare that sites are sending them spam and to start rejecting or silently throwing all messages away that come from that site, sometimes on the basis of a single spam complaint from a single user.
Sometimes, that user is a legitimate member of a mailing list from that site, and mistakenly clicked on the wrong message and clicked the "report as spam" button. Sometimes that user doesn't remember subscribing to it, so they report the message as spam. Or, sometimes the user doesn't remember how to unsubscribe, so they report the message as spam.
There's not really anything you can do about this. You are subject to the whims of the clueless users and the occasional fat-finger mistake.
Sometimes you send too much e-mail in a given period of time (or too many envelope recipients per message), so you end up tripping various other "bulk e-mail" alarms, even though there's nothing else "wrong" with your list. Sometimes this even happens if you have signed up with the ISP to be a known "large e-mail provider", so that you theoretically are allowed to by-pass the standard "bulk e-mail" thresholds.
There's not really anything you can do about this, either.
One potential solution may be to enable "personalization" for your lists (if not already enabled), and to turn on "VERP" support within your MTA. This will probably result in a performance reduction in terms of the number of mail deliveries you can handle in a given period of time, but will help make your mailing list more manageable, and may help you slide past certain ill-advised anti-spam rules. Of course, enabling personalization might also exacerbate the problem or potentially cause you to exceed other anti-spam rules. If you want to try it, take a look at the Mailman FAQ Wizard entries returned by the searches for "personalization" and "VERP" .
Otherwise, the best you can hope for is to apply to be a member of the a whitelist system if the ISP offers one, and hope that they get things mostly right, most of the time. For AOL, see http://postmaster.aol.com/tools/whitelist_guides.html. Some other large ISPs have similar systems.
AOL also has a "Feed Back Loop" form that you can fill out (see http://postmaster.aol.com/), allowing you to see all spam reports that are generated for given IP addresses. If you run a large network, it would probably be a very good idea to register your IP addresses and get reports sent back to you regarding your mail servers. Again, some other large ISPs have similar systems. For msn.com, hotmail.com and Windows Live Mail, see http://mail.live.com/mail/troubleshooting.aspx, particularly the description of the SMTP error codes and the links from the Sender services, tools, and issue submission section. For yahoo.com, see http://feedbackloop.yahoo.net/index.php.
Information about feedback loops, whitelists, etc. for several large ISPs can be found at http://wiki.wordtothewise.com/ISP_Summary_Information.
Note that this problem is not unique to AOL, they are simply one of the largest and most visible providers. Most everything said above can also be applied to other large sites, such as Yahoo!, hotmail, GMail, etc....
Unfortunately, some providers don't give you any kind of feedback mechanism as to what kind of apparent "spam" activity they see from your servers, so you never know what might be going wrong or when. Some providers don't give you any way to sign up for a "whitelist" or "known large e-mail provider" lists, so that you could bypass standard anti-spam thresholds that they might otherwise apply.
Of course, there are also anti-spam services/outsourcing firms like MAPS (http://www.mail-abuse.com/), Brightmail, Postini, etc..., and they may have totally different policies that they apply and which the customer site may have little or no control over.
Basically, if your mailing list is large enough or gets enough traffic, you may have problems with various sites that you simply cannot solve. You have to decide whether you're going to live with these problems, or if you're going to drive yourself to an early grave by worrying about things you cannot change.
For sender-side problems with Gmail/Googlemail, see FAQ 2.8 at I use Gmail-Googlemail, but I can't tell if any of my messages have been posted to the list.
Note that there are several important configuration issues for your mail server that if misconfigured will increase the likelyhood that your mail will be seen as spam.
Perhaps most important is your sending mail server should have a fixed IP address and proper forward and reverse DNS entries. See RFC 1932 and http://en.wikipedia.org/wiki/FCrDNS for more on this, but simply put, the IP address your server sends from needs a rDNS (PTR) record pointing to its host name and that host name in turn needs an A record with the same IP address. Also, it should identify itself with this same name in the SMTP HELO or EHLO command
Also, the hostname associated with that IP address should not look like a generic name from a dynamic or static block. The name should not contain the IP address or the words 'static' or 'dynamic' or other typical "one of many" features. I.e., it should be your domain, not the generic name assigned to this address by an ISP.
Also, check to see if your server is blacklisted by any of the popular blacklist services. There are tools for checking your server against multiple blacklists. These tend to come and go, but at this writing, you can check http://moensted.dk/spam/. http://www.robtex.com/dns/ also gives blacklist and DNS information for a domain.
Finally, don't look like a spammer yourself. I.e. don't import unconfirmed addresses to your list.
Converted from the Mailman FAQ Wizard
This is one of many Frequently Asked Questions.