Sophos has received reports from some customers experiencing problems sending out emails to a large number of bulk recipients.
Applies to the following Sophos product(s) and version(s) Sophos Central Email
A similar bounce back may be seen from the sender before February 12th at 15.00 UTC.
554 5.7.28 Mail flood detected;
The following notification may also be seen on the administrator dashboard:
As of 15:00 UTC February 12th, 2020, the thresholds have been reverted.
In preparation of the rate-limits being introduced, bulk email senders can request bulk sender privileges to high volume mailboxes.
Under Central Email > Mailboxes > Select the mailbox and click Request bulk sender privileges and fill out the request form.
This article will be updated when information becomes available.
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