Mail storage and access.
WHAT IT IS
A server providing mail access, with mailbox storage and indexing.
WHAT STORAGE FORMATS EXIST
One file per message in a directory structure A format storing several messages per file with indexes
WHAT THE SECOND PROVIDES
Better performance with large mailboxes, at the cost of a proprietary format.
WHAT INDEXES DO
Accelerate searching and state tracking.
WHERE TO PUT THEM
On fast storage, separate from message data where volume is large.
WHAT AUTHENTICATION OPTIONS EXIST
System accounts A database Files External directories
WHAT TO PREFER AT SCALE
A database, so accounts are managed by your provisioning.
WHAT QUOTAS PROVIDE
Limits per mailbox, with warnings.
WHAT TO CONFIGURE
A warning threshold, and what happens when exceeded.
WHAT SIEVE PROVIDES
Server-side filtering rules, applied at delivery.
WHY SERVER-SIDE
Rules apply regardless of which client is used, and work when no client is running.
WHAT TO ENABLE
Encrypted connections only.
WHAT TO MONITOR
Storage use, index health, and authentication failures.
WHAT AUTHENTICATION FAILURES IN VOLUME INDICATE
An attack in progress.
