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Mass Mails

Starting from 6 Dec 2013, please submit "Weekly Digests of CU Mass Mails" requests through the new Mass Mail System at

For individual mass mails, please submit them through ITSC Service Desk at (select category: "Accounts, Email & Portal" -> "Mass Mail") together with a completed request form downloadable at .

  1. Introduction
  2. Guidelines for Composing Mass E-mails
  3. ITSC Mass Mail Service
    3.1 Policies
    3.2 Types of Mass Mails
    3.3 Submission of Mass Mail Requests
    3.4 Definitions
  4. Resources and Related Topics

1. Introduction

University departments/units/societies/ may need to generate electronic mass mails of officially-required notification information, announcement, event/activity promotion, etc. Such mass e-mails may be accomplished by generating temporary, up-to-date electronic mailing lists, by using ITSC Mass Mail Service, or by other means of collecting e-mail addresses to reach target recipients.

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2. Guidelines for Composing Mass E-mails

Sending e-mails with large attachments, especially when reaching large batches of recipients, can cause a high server load on the e-mail system. If mass mails are not sent appropriately, they may slow down any sending or receiving of e-mails of our users, or even result in overall suspension of e-mail service in extreme cases. To help maintain the high quality of e-mail service for the whole University, you should read the guidelines below before composing your mass e-mail messages:

  1. Compress multiple files by using WinZip or WinRAR and attach one zip file in the e-mail.
  2. Convert image files from PNG to JPEG format before attaching them to the e-mail.
  3. Include links of large files uploaded to external sites instead of attaching the files to the e-mail.
  4. Consider an alternative means of mass communication provided by ITSC, such as Mailing List Service, Mass Mail Service and E-Newsletter Service.
  5. When emailing a large distribution list,
  • Check the e-mail size in the draft box before sending. A size of smaller than 150KB is preferred when sending to a group of over 1000 recipients to avoid imposing a significant impact on the network traffic.
  • Sending attachments (larger than 1MB) to distribution lists with more than 100 recipients is not recommended.
  • Dispatch the e-mail during non-office hours to avoid imposing a heavy load on the e-mail system.

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3. ITSC Mass Mail Service

ITSC provides Mass Mail Service to help University departments/units/societies to dispatch weekly digests of mass mails and individual mass mails. 


3.1 Policies

The policies below govern the Mass Mail Service of ITSC. They are created to protect CWEM e-mail users from unauthorized mass mails, and to protect the campus network and the Campus-wide E-mail System from an overload of e-mail activities.

  1. Mass mails can only be used for activities which comply with the University regulations and policies, the Acceptable Use Policy of ITSC and all existing laws including not only those that are specific to computers and networks, but also those that may apply generally to personal conduct.
  2. Mass mails should not be used to advertise or solicit commercial activities or services.
  3. Mass mails should not be used to “spam” recipients.
  4. Mass mails that are not of officially-required notification information, announcement, or event/activity promotion conducted by University departments/units/societies will not be sent.
  5. The requesting departments/units/societies must have considered all other existing channels of communication including MyCUHK, newsgroup, the web and Mailman Mailing List Service, which are more recipient-friendly, before considering the sending of mass mails.
  6. Mass mails shall be dispatched by ITSC.
  7. Dispatching mass mail is a process that imposes significant load on the Campus-wide E-mail System and the campus network. To ensure smooth running of the e-mail service for the University, ITSC has the right, in case normal service is being jeopardized, to circumvent the process including early abortion without consulting the concerned departments/units/societies.
  8. ITSC will not provide the list of e-mail addresses for the requestor’s retention.
  9. The process of handling a mass mail request includes vetting and dispatching it.
  10. For weekly digest of CU mass mails, mass mails to different groups of recipients will be grouped into different digests.
  11. ITSC reserves the right to determine when the Weekly Digest of CU Mass Mails would be sent.
  12. Mass mails will be sent to e-mail addresses in the form of "" of the target recipients.
  13. ITSC does not and has no way to guarantee the staff/students will read the mass mails delivered to their mailboxes.
  14. Some staff/students may input invalid e-mail addresses, which will result in e-mail undelivered. Departments/units/societies should prepare for receiving bounced back e-mails from the e-mail system.
  15. The following disclaimer will be added in footer of mass mails to distinguish them from the other mass e-mails:

“The e-mail is sent by ITSC to (recipients) on the request of (name of department/unit/society). If you have any queries or comments regarding the policies and guidelines for mass mails by ITSC, please check or write to the ITSC Service Desk at

For comments and enquiries related to this message, please send to (e-mail of department/unit/society). --- (Name of department/unit/society)

* Information in brackets (  ): to be filled in by the requesting department/unit/society


3.2 Types of Mass Mails

Weekly Digests of CU Mass Mails

Mass mail requests from different University departments/units/societies to the following standing “all” groups will be consolidated and dispatched in the form of a digest:

  • All staff
  • All students
  • All postgraduate students
  • All undergraduate students

Individual Mass Mails

University departments/units/societies can also request to dispatch individual mass mails to smaller groups of staff or students as long as the requesting departments/units/societies can provide the lists of staff/student ID of the target recipient groups.

If departments/units/societies request to dispatch individual mass mails to the aforesaid “all” groups, the mass mails must be justifiable as important as well as urgent messages towards the standing “all” groups.


3.3 Submission of Mass Mail Requests


  1. Only authorized persons of the departments/units/societies can request for the ITSC Mass Mail Service.
  2. No individual may request the sending of mass mail by ITSC.
  3. Student organizations must use their society computing accounts to submit requests.

Submission Deadline

  1. Weekly Digests of CU Mass Mails
    The digests are sent on the last working day of a week. The submission deadline is 5pm on the day before the dispatch day. Requests made after the deadline will be handled in next week’s dispatch.

  2. Individual Mass Mails
    Individual mass mails will only be sent during office hours. Requests should be made at least half day before your expected dispatch date. For example, requests submitted in the morning will be handled in the afternoon on the same day while requests submitted in the afternoon will be handled in the morning the next working day.

Submission Guidelines

  1. "Weekly Digests of CU Mass Mails" requests should be made through Mass Mail System.
  2. "Individual Mass Mail" requests should be made through ITSC Service Desk (select category: "Accounts, Email & Portal" -> "Mass Mail") together with a completed request form downloadable at
  3. Requestors should provide the following information for mass mail request. The request will be rejected if any information is missing.
    • Purpose of mass mail
    • Target recipients
    • Sender’s name
    • Requesting department/unit/society (name of department/unit/society in English is mandatory)
    • Sender’s contact phone number (this will not appear in your mass mail)
    • Message e-mail address (this must be a CUHK e-mail address and will appear in the “from” field of your mass mail)
    • Message subject (subject in English is mandatory)
    • Message content
    • Disclaimer
  4. Requestors should select a correct group of target recipients in the Mass Mail System. Otherwise, the request will be rejected.
  5. The same message will not be dispatched more than two times.
  6. No information should be submitted as attachment. Requestors are responsible for filling out the mass mail request form.
  7. No attachment will be sent through this Mass Mail Service.
  8. Requestors should submit a new request in case you want to make changes to your previous submitted requests.
  9. The size of the message should be smaller than 5K.
  10. The message subject should contain no more than 300 English characters and/or 80 Chinese characters (including spaces and symbols).


3.4 Definitions

Authorized Person
An individual officially acts on behalf of a department/unit/society.

Mass Mail
E-mail transmitted to a large number of addresses and having significant potential to negatively impact network or mail system performance. Although an exact lower limit cannot be specifically quantified, most cases of campus mailings to 1,000 or more users should be considered as “mass mails”.

Officially-required Notification Information
Dissemination required by law, policy, health and safety, or other very compelling reasons.

To exploit broadcast systems for purposes beyond their intended scope to amplify the widespread distribution of unsolicited e-mail.

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4. Resources and Related Topics

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Last Updated: Apr 2014

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