E-mail attachments have become commonplace, driving up the average size of messages and clogging mail systems. Multimedia mail will only make matters worse.

If you're an e-mail system administrator and you think you're ready for the year 2000, I have bad news for you. Because new versions of Lotus Notes and Microsoft Exchange Server make it so easy to attach multimedia files to messages, you're facing an entirely different kind of Y2K problem: soaring e-mail volume.

Average message size is growing faster than the user base, according to surveys conducted by my colleagues and I at Electronic Mail & Messaging Systems, a monthly newsletter that I edit. In 1994, some 53 million corporate mail users worldwide sent an average of one message a day, each containing an average of 2,500 characters of text (with each character being represented by a byte). Now there are about 153 million users — about two and a half times as many as only four years ago — and they're sending about two messages a day, each containing an average of 10,000 (10KB) characters. Attachments account for most of the increase in message size. In short, message volume has grown twenty-fold in the past four years, from 33TB (a TB is a terabyte, which consists of a million megabytes) in 1994 to 750TB in 1998.

In the next two years, message volume will grow another fifteen-fold, from 750 TB to 11,400 TB. The user base will double again before the end of the century, but the average size of messages will grow much faster — to 50 KB or more. Even if people send only one extra message per day on average, each e-mail user will generate 60 times as many bytes of traffic in 2000 as he did in 1994.

Not only documents but multimedia file attachments will become common parts of messages. A 50 KB message consists of only one fax cover page in TIFF format, or 10 seconds of speech in WAV format, or one PowerPoint slide. If video mail comes into vogue, the average size of messages will probably rocket straight up.

Multimedia Mail

New standards such as MIME HTML, which is built into Lotus Notes 5, Eudora Pro 4.0, Netscape Communicator 5, and Microsoft Outlook 98, enable users to attach entire Web pages to a message, graphics and all. But 50 KB is actually a small multimedia message, so if users really take to multimedia messaging, messaging volumes could soar even faster than my colleagues and I predict.

Notes 5 and Exchange 5.5 are Internet-ready systems, and the cost of sending a megabyte over the Internet is very low. Messages no longer cost $50 to $100 per megabyte, as they did when X.400 value-added networks were the only wide-area e-mail system worth using. Messages now cost $2.00 to $2.50 per megabyte, with staff and equipment, not network costs, accounting for most of the expense.

Companies may be able to save money by obtaining accounts at AOL or other consumer e-mail services. For $23 a month, for example, two employees can get accounts with America Online and upload multiple-megabyte messages all day for free. Of course, it's inadvisable to depend on AOL for critical file transfers within a company, even if AOL doesn't cost much.

In any event, both AOL and corporate messaging systems are drowning in attachments. The client software they use, whether it's from AOL, Eudora, Netscape, Lotus, or Microsoft, has made it too easy to attach big files to messages. And in some cases, the ability to create and send attachments has already outstripped the network's ability to handle them. n

ERIC ARNUM is the editor of Electronic Mail & Messaging Systems, a monthly newsletter that focuses on the worldwide market for e-mail, fax, and telex. Arnum and his colleagues have monitored the average length of messages and the number of e-mail users worldwide since 1994. E-mail: earnum@rcn.com.

Accommodating Large Attachments:
The Experience of E-Mail Administrators

Some large corporate mail systems are already bursting at the seams. I discussed the problem with mail administrators at four Fortune 500 companies: a pharmaceutical company, an entertainment conglomerate, an agricultural products marketing firm, and an aluminum manufacturer. All four companies had recently migrated their mail systems to Lotus Notes or Microsoft Exchange Server from older mainframe or LAN-based messaging systems. Only one of the administrators agreed to be identified; the others asked me to withhold their names, explaining that their companies frowned on unsupervised contacts with the press.

Although some of their old mail systems could accommodate attachments, the attachment process was difficult and most users avoided it. Moreover, attachments often failed to get through because the mail systems were comprised of subsystems connected by gateways that chewed up binary files. For example, the pharmaceutical company's e-mail system consisted of 17 legacy subsystems, many of which could not handle attachments. For employees at this company, sending a disk to a colleague by FedEx was usually a more efficient and reliable way of sending a file than e-mailing it as an attachment.

The Pharmaceutical Company

For years, "the only service level we were able to guarantee was a single ASCII text message end-to-end," recalled the pharmaceutical company's mail administrator. "We couldn't guarantee attachments. We couldn't even guarantee distribution lists, because sometimes some of the mail systems were stripping those out."

His company is migrating 7,000 users to Exchange in a three-year project slated for completion later this year. With most employees now using Exchange, they're sending attachments with abandon, which has created a new and unexpected problem: employees sometimes can't read their colleagues' attachments. It isn't enough to standardize on a single e-mail system, he explained; you also have to standardize on application file formats as well. In fact, it isn't even enough to standardize on Microsoft Office, he said, since one year's version of the software may be incompatible with another year's.

"This is actually becoming disruptive," he continued, wasting employees' time. "So we are now following our e-mail standardization with a desktop standardization, synchronizing all of our desktop packages with version control."

In an effort to cut down on storage requirements, he's limiting both the size of mailboxes and the amount of time they retain messages. Mailboxes are 70 MB each, and all messages are sent to a recycling bin after 60 days; the bin is emptied a week later. The restrictions make users clean up after themselves, he said, and peer pressure makes them reluctant to send big attachments. He encourages users to place large files in the shared areas of Exchange, where files aren't deleted after 60 days, and then to send out pointers to the shared folders.

The Entertainment Conglomerate

The problem of large attachments is especially acute at the entertainment conglomerate, because employees frequently have to send huge multimedia files, consisting of sound and video, between the company's offices in Los Angeles and New York.

"We've always allowed up to 20 MB to be sent," the company's mail administrator explained. "The messages may be delayed to after hours, but we will allow that. In our business, you can't say 'you can't do that,' because they may need to zap something from coast to coast. You've just got to figure out how to do it. We have separate queues for the big messages, and we delay them to the non-prime hours." If more bandwidth is required, he adds more bandwidth. If more disk drives are needed, he adds a few more gigabytes to the server cluster.

The Agricultural Products Company

The Continental Grain Co., based in New York City, used to have a Banyan e-mail system that handled attachments well. But the company, one of the largest marketers of agricultural products in the world, has switched to Notes, which makes sending attachments a cinch. As a result, said mail administrator William Klauk, Continental Grain has been hit with big bills from the value-added networks the company uses for remote deliveries.

"We've had occasions where as we converted over from our old mail system to Notes," he explained, "the ease at which they can include attachments now causes problems." Some new Notes users have unthinkingly sent attachments to every name on a long distribution list — and some of the names on the list were remote users linked through gateways to a value-added network. In one of the most egregious incidents, the company was charged $5,000 for a 15 MB bitmapped file sent to India.

Continental Grain hasn't imposed a maximum message size. But the Internet mail servers of some of its trading partners have per-message limits on the inbound side, so senders' messages, including attachments, often get bounced back, taxing network resources twice.

The Aluminum Manufacturer

For the aluminum manufacturer, large file attachments are already a big problem. The company recently migrated from Lotus cc:Mail, where maximum mailbox sizes were kept at 1 MB, to Exchange, where a single PowerPoint file can easily consume 1 MB. In an effort to keep its message store under one terabyte, the company limited mailboxes to 20 MB, and messages to 2 MB.

"The biggest issues I have with the store are operational issues such as recovery time," said the company's mail administrator. Even limited to a terabyte, the store can get so large that it takes a day or longer to bring the system back up if it crashes. As a result, he encourages users to send pointers to HTML pages or shortcuts to PowerPoint files; if they must send attachments, they're asked to compress them. "In some ways, the Web has come along to help the problem from getting totally out of hand," he said. "People internally are told to send links rather than the stuff itself."

But Attachments Live On

As much as administrators want users to send pointers to shared files, users are reluctant to comply: it's often easier to distribute an attachment by e-mail than to post it in a shared file. As a result, e-mail is turning from a means of exchanging text messages into a general-purpose pipeline between applications. And those applications, especially the ones that use multimedia, can easily generate huge files.

"Things are better and easier," said the aluminum company's mail administrator. "We're sort of victims of our own success. I think there's a flood coming out there that could possibly overwhelm us. I worry when I hear people say they can get their pictures developed on the Internet."

— Eric Arnum