Start/notes.ini Parameters/NoMsgCache

NoMsgCache

Parameter: NoMsgCache
Short description: Disables per-user message caching by the IMAP task. Reduces memory consumption but can slow down individual IMAP operations.

Profile

Parameter
NoMsgCache
Category
Mail / Router (IMAP)
Available since
At least 9.0.1 (HCL documentation)
GUI equivalent
notes.ini only (no GUI)
Possible values
Setting/presence enables the behavior (typically 1)
Default
Cache active (parameter not set)

Description

According to HCL product documentation:
This setting disables per-user message caching by the IMAP task. This can improve capacity (number of users) on a server by reducing memory consumption. However, response time for some user operations may be slower.
With NoMsgCache, the administrator instructs the Domino server not to keep per-user caching of the IMAP message headers in memory. This is a tuning trade-off:
  • Advantage: less RAM consumption → more IMAP users per server
  • Disadvantage: individual IMAP operations (listing, search) may be slower because they have to be read from the database again and again
Useful on servers with many IMAP users and comparatively little RAM — not useful with a few power users who need fast IMAP response times.

Example configuration

NoMsgCache=1

Notes & pitfalls

  • Only takes effect for the IMAP task — POP3 and Notes clients are not affected.
  • When enabling, typical IMAP operations (folder open, header retrieval) should be measured and compared with the previous state.
  • Can be combined with other IMAP tuning settings (e.g. IMAP session timeout, number of mailboxes).

Sources (HCL Product Documentation)