Limits Hierarchy
You can specify limits on outgoing mail at the following levels: Mail
server > service plan > subscription > domain and mailbox.
The limits that you specify in Server-Wide Mail Server Settings act
as defaults for Plesk objects at all lower levels of hierarchy.
However, if you set custom limits at some level of hierarchy, then
these custom limits will act as defaults for lower levels. For example,
if you set custom limits for a service plan, the plan’s limits act as
defaults for subscriptions created under this plan. Similarly, a
subscription’s custom limits act as defaults for its domains and
mailboxes.
The values of custom limits can be greater than the default values.
Customers can change their limits only at the domain and mailbox levels.
How Limits Work
The number of outgoing email messages sent from a parent object (such as
a subscription) is counted as the sum of email messages from its child
objects (such as domains). Therefore, limits work in the following way:
- The sum of messages from all domains of a subscription cannot be
greater than the subscription’s limit. - The sum of messages from all mailboxes of a domain cannot be greater
than the domain’s limit.
Note: The limit of a parent object is more important than individual limits
of child objects. For example, if the limit for a subscription is
reached, no domains of this subscription can send mail, even when
some of the domains have not yet reached their individual limit.
Similarly, if the limit for a domain is reached, no mailboxes of this
domain can send mail, regardless of the fact that some of the
mailboxes have not reached their individual limit.
If a user or a script sends an email message by using the Linux Sendmail
utility, then Plesk counts this outgoing message for the corresponding
domain in case the script is handled by mod_apache
(mod_php, mod_perl, mod_python, and so on). In other cases (CGI,
FastCGI), Plesk counts the outgoing message for the corresponding
subscription, but does not count it for the corresponding domain. A
script or a user can send messages using Sendmail if the option Allow
scripts and users to use Sendmail is switched on for a
subscription.