IMAP Quota and Service Policies

Service Max msg (MB) Max recipients Mailbox quota (MB) Access/Activity (days)
SMTP (See Note 1) 25 100 n/a n/a
IMAP n/a n/a 100/500 90 (see Note 2)
POP3 (See Note 3) n/a 500 (See Note 4) 90 (See Note 4)
RESPITE n/a n/a n/a 21/28 (see Note 5)
WebMail 10 100 500 (see Note 6) n/a


  1. The SMTP limits in some cases exceed those of other mail servers. It is possible to send a message to which will be rejected by other mail servers either because it is too large, or has too many recipients, or the recipient's mailbox is over quota. If you receive a bounced email message, first read it to determine which server bounced the email, and why it bounced.
  2. Inactive accounts, defined as those for which there has been no IMAP or POP3 activity for 90 days, have a quota of 100 meg. New accounts start with the 100 meg quota, which is increased once the account is active.
  3. POP3 limits connections to once every 5 minutes. But, this is a soft limit with a 60 connections padding. This allows bursts of activity, and accomodates clients that check on send. If you check for POP3 email every 5 minutes you will likely never see this limit. If you check for email every 1 minute the padding will run out after 72 minutes (1 hour, plus the 12 added during that hour). If you need to check for new email more frequently, we recomend using Thunderbird configured for IMAP. Thunderbird supports IDLE-mode, which will tell you of new email the moment is is available on the IMAP server.
  4. POP3 is a subset of IMAP which views only in the INBOX. It is designed for older email clients. POP3 and IMAP email both reside on the same server, and share the same quota. IMAP folders other than INBOX cannot be viewed by a POP3 client, but their contents count against email quota.
  5. Messages trapped by RESPITE will be held for 21 days before being deleted. Users can configure RESPITE to send them an email when messages are trapped. After 28 days all records of the message are deleted from the RESPITE database. Messages marked as spam are cleared from the database after 7 days.
  6. WebMail is an IMAP client, and so is subject to that server's storage restrictions.