Mailsphere notification emails are being rejected

Mailsphere delivers quarantine reports, antivirus and attachment filter notices as well as profile update notices via the notification@mailsphere.mx email address.

When replacing other email security gateways it is important that the existing receive connectors are disabled once Mailsphere is live.  Without this it is possible that the previous email security gateway may be still involved in the mailflow and cause delays in users receiving notification emails.

Example of a notification email blocked by a Sophos appliance

Example of a notification email blocked by a Sophos appliance

The example above shows the reported delivery failure as 550 Administrative prohibition.  This was caused by a Sophos appliance remaining active in the mailflow of inbound email.