Skip to main content

mpHigh

mpHigh = 1

Example​

procedure ConfigureImportantMessage(Message: TIdMessage);
begin
  Message.Priority := mpHigh;
end;

Usage​

mpHigh selects Velox's high mail-priority hint, generating urgent/high text headers and numeric X-Priority 2.

Additional Technical Info​

mpHigh is the second-highest TIdMessagePriority member. During normal header generation Indy emits:

HeaderValue
Priorityurgent
X-Priority2
Importancehigh

The example changes the direct enum property; headers are generated later when the message is sent or saved. It is source-reviewed and is not executed by the documentation workflow.

Behavior and boundaries

  • mpHigh differs from mpHighest only in numeric X-Priority (2 versus 1).
  • The headers are advisory display/classification hints. They do not raise Velox queue priority, accelerate SMTP, change retry policy or guarantee recipient behavior.
  • It is independent of IMAP mfFlagged, which is mailbox state rather than a message header.
  • Raw generated priority headers are overwritten during generation. Later ExtraHeaders can add duplicates or contradictions, so use one mechanism.

Input and round trips

Indy preserves mpHigh only when the first recognized priority header supplies numeric token 2, normally X-Priority. Text containing urgent or high maps to mpHighest. If an intermediary removes X-Priority but leaves Priority: urgent or Importance: high, loading then saving the message can change the generated number from 2 to 1.

Errors, performance and concurrency

Enum assignment is constant-time and does not raise. Header generation can fail for unrelated encoding/I/O reasons after updating generated headers. Do not mutate or generate one message concurrently.

Related entries

External references

Created 2026-07-15