Mail server (email server): what it is and how it is attacked
Sends, receives and stores the organisation's email.
Also known as
- email server
- Exchange
- SMTP
Typing any of them into the editor finds this object.
Why it matters on a security diagram
It is both a way in and years of accumulated sensitive content in one place.
How it gets attacked, and what reduces it
How it gets attacked
- Rules quietly added to forward mail elsewhere
- Sign-in from anywhere in the world without a second factor
What reduces it
- Alert on forwarding and hiding rules being created, which is the usual first sign
- A phishing-resistant second factor on every mailbox, including shared ones
- Review which applications hold standing access to mailboxes, because a password reset does not remove them
Where it sits
- Group
- Servers · Machines that run something for other machines.
- Whose side, by default
- Ours · Belongs to the organisation the diagram is about.
- Catalogue identifier
- mail-server
Reviewed . CC BY 4.0.
Others in servers
- Serverhost · machineA computer that runs something for other computers.
- Web serverHTTP server · websiteThe computer that sends your website to anybody who visits it.
- Application serverbackend · business logic tierRuns the working parts of an application, behind the website.
- DatabaseDB · SQL server · data storeStores the organised information an application depends on.
- Name serverDNS · domain name serverTranslates names like example.com into network addresses.
- File serverSMB server · network shareHolds shared documents everyone can reach over the network.
- Virtual machine hosthypervisor · ESXi · Hyper-VOne physical server pretending to be many.
- Jump hostbastion · jump box · hardened admin hostThe single controlled machine administrators go through to reach sensitive systems.
- Backup serverbackup · Veeam · backup controllerMakes and manages the spare copies of your data that let you recover after something goes wrong.
- Update serverWSUS · patch server · software distributionDistributes software updates to every machine.
- Build pipelineCI/CD · Jenkins · GitHub ActionsThe automated production line that turns written code into the software the business actually runs.
- Phone systemVoIP · PBX · telephony serverRuns the organisation's telephone calls over the network.
The servers group lists all 13 of them side by side.
Mail server on your own diagram
Open the editor, press N, and type email server. The object is placed and connected to whatever was selected, and Tab adds the next one already joined to it. Nothing is uploaded: the page is served with a Content Security Policy that forbids the browser from making any outbound request at all.
Open the diagram maker