With Intel announcing the End-of-Life to Mc Afee Saa S Email Protection, it has been suggested that if you have a large number of mailboxes (let’s say 10,000 or more), you should only consider vendors cited in sources like the Gartner list.

As email marketers we definitely want to avoid sending spam and putting our emails at risk of being mislabeled as spam.
One of the ways that keep email marketers honest about using 100% opt-in email lists are the use of spam traps.
Product datasheet Upgrade Price Guarantee Compatible with Windows 10, 8.1, 8, 7, Vista and XP, 32 Bit / 64 Bit Editions New language versions: Chinese - Lithuanian - Japanese - Polski - Romanian - Spanish - Czech Update Star is compatible with Windows platforms.
Update Star has been tested to meet all of the technical requirements to be compatible with Windows 10, 8.1, Windows 8, Windows 7, Windows Vista, Windows Server 2003, 2008, and Windows XP, 32 bit and 64 bit editions.
The Client Access server role hosts the Frontend Transport service, which provides filtering of email traffic (eg antispam agents), and routing of email between the internal Exchange servers and the outside world The Mailbox server role hosts two additional services: Get-Service | Where Display Name -like "*Transport*" | Select Display Name Display Name ----------- Microsoft Exchange Frontend Transport Microsoft Exchange Mailbox Transport Delivery Microsoft Exchange Mailbox Transport Submission Microsoft Exchange Transport Microsoft Exchange Transport Log Search No matter whether the server is multi-role or only installed with the Client Access server role, the Frontend Transport service is the only service already listening on TCP port 25 (SMTP).
The other services listen on a variety of other ports (for example TCP 2525 for the Transport service).
This approach frees up your internet bandwidth and prevents internet and email borne threats from reaching your network, your servers, desktops, or inboxes. [email protected] antispam is a managed antispam service geared towards service providers and companies who have their own dedicated mail servers.
Flat rate pricing per mail server means no more paying per mailbox!
The Client Access server role is configured with a receive connector called “Default Frontend SERVERNAME” that is intended to be the internet-facing receive connector, so is already set up to receive SMTP connections from unauthenticated sources and allow them to send email to internal recipients.