Email Basic Guide

Quick Summary

Email quota per account
  • 100 GB for staff  (Exchange Online) and students (@Connect)
  • 10 GB for project account (on-premises Exchange 2013)
  • 50 GB for alumni (@Connect)

NB: Quota includes inbox and all other mail folders. Check your mailbox usage regularly

If quota reached
  • Staff  (Exchange Online) and students (@Connect) :
    For Staff users, you can email to to turn on Online Archive Mailbox after reached 90GB.
    1. Warning issued at 98 GB
    2. Cannot send at 99 GB
    3. Cannot send/receive at 100GB
  • Project account (on-premises Exchange 2013):
    1. Warning issued when usage exceeds 95% of quota
    2. Cannot send/receive mail when mailbox is 100% full, with senders receiving a bounce back message
  • Alumni (@Connect):
    1. Warning issued at 49 GB
    2. Cannot send at 49.5 GB
    3. Cannot send/receive at 50GB

NB: Keep monitoring your usage to avoid late delivery of incoming email, and archive older or less frequently used mail.

Maximum size of outgoing message
  • 10 MB for mailing lists
  • 35 MB for students
  • 50 MB (server:
  • 100 MB among staff users
Maximum number of recipients per outgoing message
  • 500 email addresses (Office 365 users) 1
  • ~250 – 260 (Outlook Client)
  • 300 email addresses (server:

NB: To email larger numbers of recipients, use the mailing list service.