Documentation
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Overview ¶
Package queue implements module which keeps messages on disk and tries delivery to the configured target (usually remote) multiple times until all recipients are succeeded.
Interfaces implemented: - module.DeliveryTarget
Implementation summary follows.
All scheduled deliveries are attempted to the configured DeliveryTarget. All metadata is preserved on disk.
Failure status is determined on per-recipient basis:
- Delivery.Start fail handled as a failure for all recipients.
- Delivery.AddRcpt fail handled as a failure for the corresponding recipient.
- Delivery.Body fail handled as a failure for all recipients.
- If Delivery implements PartialDelivery, then PartialDelivery.BodyNonAtomic is used instead. Failures are determined based on StatusCollector.SetStatus calls done by target in this case.
For each failure check is done to see if it is a permanent failure or a temporary one. This is done using exterrors.IsTemporaryOrUnspec. That is, errors are assumed to be temporary by default. All errors are converted to SMTPError then due to a storage limitations.
If there are any *temporary* failed recipients, delivery will be retried after delay *only for these* recipients.
Last error for each recipient is saved for reporting in NDN. A NDN is generated if there are any failed recipients left after last attempt to deliver the message.
Amount of attempts for each message is limited to a certain configured number. After last attempt, all recipients that are still temporary failing are assumed to be permanently failed.
Index ¶
Constants ¶
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Variables ¶
This section is empty.
Functions ¶
Types ¶
type Queue ¶
type Queue struct {
Log log.Logger
Target module.DeliveryTarget
// contains filtered or unexported fields
}
func (*Queue) InstanceName ¶
type QueueMetadata ¶
type QueueMetadata struct {
MsgMeta *module.MsgMetadata
From string
// Recipients that should be tried next.
// May or may not be equal to partialError.TemporaryFailed.
To []string
// Information about previous failures.
// Preserved to be included in a bounce message.
FailedRcpts []string
TemporaryFailedRcpts []string
// All errors are converted to SMTPError we can serialize and
// also it is directly usable for bounce messages.
RcptErrs map[string]*smtp.SMTPError
// Amount of times delivery *already tried*.
TriesCount map[string]int
FirstAttempt time.Time
LastAttempt time.Time
}
Source Files