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Why BCC can be bad thing for large email distribution lists (and what to do about it)

If you work at a large company like I do, then you probably participate in at least a handful of email distribution lists. An email distribution list is a single email address (e.g. example@microsoft.com) which allows you to send a mail to one address which is then delivered to 1 or more people (potentially even thousands of people).

A common practice is to use inbox filtering rules (such as those offered by Microsoft Outlook) to route mail sent to these distribution lists into a subfolder in your inbox. This way when I’m interested in catching up on the latest discussions on a particular topic I can browse that subfolder instead of being constantly barraged with such messages in my main inbox.

So far so good, right? The problem that happens is when somebody decides to take a discussion “offline” by BCC’ing the distribution list. The intention is good, and goes something like this:

Original mail From:
Joe
To: Widgets Discussion
Hey everybody! I need help selling a Widget to my customer in North Dakota. Who can help? – Joe

Reply: From:
Steve
To: Joe
Bcc: Widgets Discussion
Hi Joe,
I can help, let’s take it offline. Bcc’ing Widgets Discussion. – Steve

Now when Joe replies he will only be replying to Steve, since there’s no need to involve the rest of the Widgets Discussion distribution list. This reduces “noise” for the rest of the Widgets Discussion recipients who don’t need to be involved with Joe and Steve’s ongoing sale discussion. Good, right? Yes, but the problem is that when Steve bcc’d the Widgets Discussion alias it broke inbox filtering rules. Inbox filtering rules such as these rely on knowing that the message was sent to the Widgets Discussion alias in order to route it to the appropriate inbox subfolder – but with a bcc you don’t get that information (that’s the whole purpose of a blind carbon copy). Now every one of the hundreds (thousands?) of people on the Widgets Discussion alias just got a message in their inboxes that they have to manage (e.g. delete) instead of just having that message land in the appropriate subfolder.

So what’s the alternative?

A much better alternative which allows for the inbox filtering rules to continue to operate and for Steve to take the discussion offline is for Steve to simply send two mails. So the conversation would go like this:

Original mail From:
Joe
To: Widgets Discussion
Hey everybody! I need help selling a Widget to my customer in North Dakota. Who can help? – Joe

Reply to all: From:
Steve
To: Joe; Widgets Discussion
Hi Joe,
I can help, let’s take it offline. I will email you separately. – Steve

Private reply : From:
Steve
To: Joe
Hi Joe,
I’d love to help. I’ve sold lots of Widgets in North Dakota. Do you have time on Thursday to meet? – Steve

Notice that the first reply was sent to everybody, and the second reply was sent only to Joe. This extra step takes a few extra seconds on behalf of Steve, but can save the hundreds or thousands of people on the Widgets Discussion from getting the “inbox spam” which occurs when the act of BCC’ing breaks your inbox filtering rules.

Think this could work for you or somebody you know? Please pass it along! Here’s an easy-to-remember URL: https://tinyurl.com/FightInboxSpam

Comments

  • Anonymous
    September 09, 2009
    The comment has been removed
  • Anonymous
    September 09, 2009
    Hi Craig, In theory, yes. However in practice what I usually see happen is that:
  • Joe will reply all, continuing the "noise" for the broader distribution list, even if Steve said something like "reply directly to me and I'll help you" ...or, more likely...
  • When Steve replied he actually wants to add Bob, Sharon, and Team North Dakota (another distribution list) to the ongoing discussion. In this case you want Joe to reply all to continue the discussion with the new set of people but you don't want to include Widgets Discussion. So in my example Steve would send one mail to Widgets Discussion saying he's taking it offline, then another mail with the intended recipients.
  • Anonymous
    September 10, 2009
    So true, but you know that people don't typically take that extra 2 seconds to think about the inbox group email abuses of the mass reply. Thanks for this tip, I will pass it along!

  • Anonymous
    August 25, 2016
    At first, sounds very clever. But wait. Why should be re-educate people of what they've been doing for decades? It is the rule creation that is not handling this generic practice, not the people performing their normal jobs. We should as the email application / server rule creation tool to remind this problem and properly handle this situation. Don't treat people with old habit as dumb. It could be the modern tool that does not know of the old habit that is dumb.

    • Anonymous
      August 25, 2016
      Sure, I appreciate the sentiment of what you're saying. I'm not saying people are dumb. A lot of very smart engineers I work with BCC large DL's and I send out a link to this blog post on a near weekly basis. Heck, I made the same mistake before somebody taught me. But getting back to your suggestion, the very nature of BCC is that the client is blind to the distribution list. If you were to "fix" rules so that they could do different things based on the contents of the BCC field, then you would in effect be breaking the promise of BCC. So there's not really an engineering solution here. It starts with educating people and nudging their behaviors.