Add parameter to API function hold_outgoing_email to control email notifications back to sender

As a system administrator, I would like to add a parameter to the API functions hold_outgoing and suspend_outgoing_email so that I can control whether email notifications are sent back to the sender for messages queued after a hold or suspend has been activated for outgoing email.

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Add a parameter to the API functions hold_outgoing_email and suspend_outgoing_email to control whether email notifications are sent back to the sender for messages queued after a hold or suspend has been activated for outgoing email.

Currently, when an outgoing email hold or suspension is activated via the API and an outgoing email is subsequently attempted for delivery, an email notification is sent back to the sender that says:

(for a hold): "Domain example.com has an outgoing mail hold. Message will be reattempted later"

(for a suspension): "Domain example.com has an outgoing mail suspension. Message discarded."

In cases where a script that sends email wants to intentionally delay delivery until after the script is finished, it may wish to call hold_outgoing_email during processing and queuing, then release_outgoing_email at the end of the processing, allowing the system to resume delivery of outgoing messages queued during the process. In this use case, it is undesirable to have email "error" messages sent back to the email sender warning them about the hold or suspension.

Adding an additional parameter to the hold and suspend API functions to disable notifications would be helpful in these cases.