Once upon a time, running a mailing list involved all manner of arcane commands. Thanks to Yahoo!Groups and similar services, anyone who can get on the web can run a list now. Online communities have sprung up for absolutely every interest, enabling people who’ve never heard of old-fashioned Usenet to exchange information with thousands of others across the world.
Unfortunately, spammers have discovered that they can often get spam through to Yahoo!Groups lists, simply because most of the list owners aren’t very experienced in list management.
I own or moderate a fair number of lists hosted by Yahoo!Groups. I can proudly say that spam doesn’t get through to any of them, and hasn’t since I took them over (if I didn’t create them in the first place).
It isn’t actually very difficult to accomplish the same for your lists, but you do need to think ahead a bit.
First, you control who gets on your list. Yahoo! has made it difficult for automatic software to join lists, as they did at one time. Still, there are spammers who do nothing but go through lists of groups and join them. You don’t want them on your list.
Set up a message that is automatically sent to every person who requests membership. That list should explain a statement of the purpose of your list and any list guidelines you have. As the recipient to reply to it with an introduction explaining why they want to join your list, and a statement acknowledging their receipt of and intention to follow your list guidelines.
That introduction will take a sincere person just a few minutes. Spammers will never respond. It isn’t worth their time.
There are, unfortunately, a few people who will go through the introduction process, then start sending advertisements to your list. Your second safeguard is to place all new list members on moderated status for some period of time that you choose. I’ve used anything from a week to a month, depending on the list. I do not tell the new members that they will be moderated at first, as I don’t want them to pretend to make nice ’til their trial period is over.
If someone does send advertisements to your list, don’t just kick them off the list. Ban them. Yes, they could come back using another email address, but if you’re paying attention you’ll likely catch them out with step one.