We get asked this question quite a lot because people think it’s a cheap way of running a mailing list.

The problem is that the BCC was not intended to be used in this way - it is intended to be a method of copying a small number of people (usually one or two) into a communication without the actual addressees knowing. This is useful to keep people “in the loop” on an issue so that they have the backstory when they need to get involved.

However, spammers (in particular) have abused the BCC field, and through their actions have effectively outlawed it as a method of operating a legitimate mailing list.

Here are a few reasons why it’s bad:

• The number of BCC addresses is normally limited to a small number of recipients. 50 seems to be quite common but it can be lower. Consequently, larger mailing lists need to be split into multiple messages.
• Companies operating mail servers look for patterns in mail messages to determine if they are spam or you are a spammer. So, if you do split your campaign up into multiple messages using BCC to split the list and then send these messages off through your mail account, your ISP could happily drop (delete) some or all of your outgoing messages because they look like you are spamming (it’s called acceptable use and you are in breach). In the worst case, you could have your account suspended.

If your messages do manage to get out through your ISPs mail server, they have to contend with the recipients mail servers. Here, they go through the same types of checks as your outgoing server plus a lot more. Here are some of them:

• The intended recipient is not listed in the TO field could cause your email to be treated as spam - since you used the BCC field you will always fail this test and a lot of emails disappear this way. A further check to see if the recipient (TO) is the same as the sender (FROM) adds weight to the “might be spam” check; “legitimate” senders often send a message to themselves and BCC everyone else - however, this looks like spam to the spam filters (spammers fake email addresses in the FROM and TO fields)
• If you’re using HTML emails, use high quality HTML emails. Don’t use tools which generate horrendous HTML (example: MS Word). They often leave signs behind (like empty tags, eg: <b></b>)Â which are generally found in spam. Make sure your HTML is valid (run it through a decent validator). Unbalanced tags and invalid tags will also flag an email as spam. If you use a title, make sure the title is meaningful — the default titles generated by HTML tools are often used as spamsign.
• Use email composition and mailing tools that work correctly. Well constructed emails (technically correct) can be readily identified as not-spam. Emails with missing mime sections, invalid or missing date headers, subject lines or other headers with unescaped unicode, etc., are frequently signs of spam. A mime section is a part of the email message - for example, if you use Outlook to compose an HTML (pretty) email message then there will only be an HTML mime section (the part that contains the HTML message). As a general rule, safer emails should have a plain text mime section AS WELL so that they are better welcomed by the recipient ISP’s spam filters.

There are many, many more reasons why an email could be thought of as spam, and you can read more about possible problems at this article on the SpamAssassin site (we also use SpamAssassin on our servers).

So in summary: no, it’s not OK to use BCC for a mailing list.

Here are some alternatives:

• Use systems such as Mailman (we operate this system on our servers). Cost: Nil.
• Install something like phpList. Cost: The annual cost of adding a mySQL database to your hosting plan; Maintenance charges to upgrade the system to new versions when they are released
• Use a third-party system like Campaign Monitor. Cost: USD5 + USD0.01 per recipient per mailing
• Outsource (we use both of Mailman and Campaign Monitor). Cost: Design & Consultancy, plus any distribution costs

(These costs do not include any installation or configuration tasks that may be required).

Systems like Mailman provide a “basic” system that allows you to build and run large mailing lists. Under the surface it is a sophisticated system as it manages subscriptions, unsubscribe requests, bounced emails and much, much more. Once you have set it up, is all you need to do is send your email TO the mailing list and Mailman does the rest, sending your message individually to each person on your mailing list.

Systems like Campaign Monitor give you a host of marketing tools to compliment your campaigns. As well as the standard subscription and bounce management, you can view open rates and other statistics so you can track how your messages are being viewed. The online interface for managing your list is also much more user friendly, but you get what you pay for!

Open source systems like phpList sit somewhere between the two, providing a mixture of standard and enhanced features. The risk (for hosting companies) with systems like phpList is the load they place on the server. Because they are installed on your website, they need to use PHP to generate and send the emails, so larger mailing lists (e.g. > 1750) will put a heavy load on the server; systems like Mailman operate at a different level and so don’t have this immediate performance impact.

Outsourcing is always a good option if you don’t want the hassle, or (more likely) need your emails to be on brand and consistent in appearance. Your design/marketing company will ensure that all email campaigns are produced to the same standard (so you don’t need to learn how to code them or abuse your brand guidelines) and sent using an appropriate system. Of course, outsourcing costs more because you have to pay for the service of producing the email layouts and that’s a value decision for your business.