A simple approach for eliminating spam

Letter to the Editor

A simple approach for eliminating spam

Sasha Mazzarello, BSc
Ottawa Hospital Research Institute and Department of Medicine, University of Ottawa Ottawa, Ontario.

Michael Fralick, MD
Department of Medicine University of Toronto, Toronto, Ontario.

Mark Clemons, MD
Ottawa Hospital Research Institute and Department of Medicine, University of Ottawa and Division of Medical Oncology, The Ottawa Hospital Ottawa, Ontario.

doi: http://dx.doi.org/10.3747/co.23.2860

The Editor

Current Oncology

6 August 2015

In recent years, the incredible expansion of e-mail has changed the way we all practice medicine. Although the change has had both positive and negative implications, physicians are undoubtedly spending an increasing amount of their time responding to e-mail1,2. However, approximately 85% of received mail is spam, and people therefore have to spend a significant amount of time distinguishing spam from legitimate e-mail3.

Spam senders usually obtain e-mail addresses from commercial vendors, by harvesting Internet mailing lists, or by using software to search the Web Spam recipients are left with no choice but to press the Delete key or try to opt out of each unsolicited communication received.

Spam is not only frustrating, it is also a prime medium for phishing (e-mails fabricated by fraudulent senders to collect sensitive information) and malware spread3. Spam-filtering software can apply statistical approaches to classify e-mail as spam or a legitimate message, and most applications make use of techniques to fight it.

Anti-spam legislation has been passed by 34 countries. The Canadian4 and U.S.5 legislation both require that senders of commercial electronic messages to an electronic address obtain consent from the recipient and that they provide sender identification information and an unsubscribe mechanism in all messages45. For the purpose of the present communication, we therefore decided to assess the effectiveness of unsubscribing from sources of incoming spam. Moreover, if unsubscribing failed to prevent subsequent e-mails, we decided to threaten legal recourse per the recent Canadian legislation.

From 12 December 2014 to 20 April 2015, all unsolicited e-mails sent to one medical oncologist (MC) were collected. Requests to unsubscribe from the sender’s mailing list were made upon e-mail arrival. If an unsubscribe mechanism was not available, an e-mail was sent to the sender requesting to unsubscribe. During the period of interest, 217 e-mail messages from 81 different senders were received. Of the 81 senders, 15 (19%) did not provide an option to unsubscribe. Most senders (73%) stopped sending e-mail messages after a single request (Figure 1). On 15 March 2015, an e-mail message was sent to those who continued to send e-mail messages after a request to unsubscribe (16%) and to those who did not provide a mechanism to unsubscribe (19%). The e-mail stated that if the spam did not stop, the source would be reported to the Spam Reporting Centre established under Canada’s Anti-Spam Legislation4:



FIGURE 1 Number of e-mail senders during each phase of the study.


We have asked to be unsubscribed from your mailing list. You have failed to do so. As per national anti-spam laws, if more emails come from you we will report you to the Canadian Anti-Spam Legislation.

After 15 March 2015, all 28 senders notified stopped sending e-mail messages.

The rapid growth of spam significantly threatens the overall stability, effectiveness, and efficiency of e-mail as a vital tool for everyday personal and professional communication. For physicians, deleting spam takes time that would otherwise be used in other duties. The battle to minimize spam is basically the responsibility of the user. A number of investigations by the Canadian Radio-television and Telecommunications Commission are currently under way. Indeed, Porter Airlines recently paid CA$150,000 for violating Canada’s Anti-Spam Legislation because they sent commercial e-mail messages that did not offer an unsubscribe mechanism6. Thus, to prevent ongoing receipt of spam, the choice is to simply continue to press the Delete key or to take a more proactive approach. If selecting the unsubscribe request fails to work, then a little note pointing out that the sender’s spam is in violation of the anti-spam law might just do the trick.

Please let us know how things go!


We have read and understood Current Oncology’s policy on disclosing conflicts of interest, and we have none.


1. Mazzarello S, Clemons M, Graham ID, Joy AA, Smith S, Jacobs CM. Third-party online surveys—science, selling, or sugging? Curr Oncol 2015;22:182–3.
cross-ref  pubmed  pmc  

2. Geynisman DM. e-Mail anonymous: a physician’s addiction J Clin Oncol 2015;33:285–6.

3. Laorden C, Ugarte-Pedrero X, Santos I, et al. Study on the effectiveness of anomaly detection for spam filtering. Inf Sci (NY) 2014;277:421–44.

4. Canadian Radio-television and Telecommunications Commission (crtc). Compliance and Enforcement Information Bulletin CRTC 2012-548. Ottawa, ON: crtc; 2010. [Available online at: http://www.crtc.gc.ca/eng/archive/2012/2012-548.htm; cited 4 April 2015]

5. United States, Federal Communications Commission (fcc). Spam: Unwanted Text Messages and Email [Web page]. Washington, DC: fcc; 2014. [Current version available at: http://www.fcc.gov/guides/spam-unwanted-text-messages-and-email; cited 27 April 2015]

6. Canadian Radio-television and Telecommunications Commission. Archived – Porter Airlines Inc. agrees to pay $150,000 for allegedly violating Canada’s anti-spam law. [news release]. Ottawa, ON: Government of Canada; 2015. [Available online at: http://news.gc.ca/web/article-en.do?nid=993469; cited 5 August 2015]

Correspondence to: Mark Clemons, Division of Medical Oncology, The Ottawa Hospital Cancer Centre, 501 Smyth Road, Box 912, Ottawa, Ontario K1H 8L6. E-mail: mclemons@toh.on.ca

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Current Oncology, VOLUME 23, NUMBER 1, February 2016

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ISSN: 1198-0052 (Print) ISSN: 1718-7729 (Online)