Quota Backend: count

New in version 2.2.19.

The count quota backend tracks the quota internally within Dovecot’s index files. It is the RECOMMENDED way of calculating quota on recent Dovecot installations.

Each mailbox’s quota is tracked separately and when the current quota usage is wanted to be known, the mailboxes’ quotas are summed up together. To get the best performance mailbox list indexes should be enabled.


If you’re switching from some other quota backend to count, make sure that all the mails have their virtual sizes already indexed. Otherwise there may be a significant performance hit when Dovecot starts opening all the mails to get their sizes. You can help to avoid this by accessing the mailbox vsizes for all the users before doing the configuration change: doveadm mailbox status -u user@domain vsize '*'.


mailbox_list_index = yes

# Avoid spending excessive time waiting for the quota calculation to finish
# when mails' vsizes aren't already cached. If this many mails are opened,
# finish the quota calculation on background in indexer-worker process. Mail
# deliveries will be assumed to succeed, and explicit quota lookups will
# return internal error. (v2.2.28+)
protocol !indexer-worker {
  mail_vsize_bg_after_count = 100

plugin {
  # 10MB quota limit
  quota = count:User quota
  quota_rule = *:storage=10M

  # This is required - it uses "virtual sizes" rather than "physical sizes"
  # for quota counting:
  quota_vsizes = yes