May 05, 2017: Automatically manage connection settings in Mail on your Mac - Apple Support Mail automatically adjusts certain connection settings to keep your email working. In OS X Yosemite v10.10 or later, Mail takes the following actions whenever it can't connect to your email provider to send or receive email. The Firewall - Network Monitor application gives you the full control over your Mac, protects the privacy of your computer, prevents unwanted network connections. Network Monitor - discloses outgoing, incoming connections to your Mac - keeps records of the applications’ actions - reveals hidden services running on the computer Network Filter.
- Block Outgoing Connections Firewall
- Block Incoming And Outgoing Connections
- Mac App To View Outgoing Connections Email
- Mac Check Outgoing Connections
Mail User Guide
You can change preferences for the SMTP mail server you use to send messages, as directed by the provider of your email accounts.
To change these preferences in the Mail app on your Mac, choose Mail > Preferences, click Accounts, click Server Settings, click the outgoing Account pop-up menu, then choose Edit SMTP Server List.
Option | Description |
---|---|
Server list | The servers available to you and the accounts that are using them. |
Add , Remove | Add or remove a server. Don’t remove a server that’s in use by an account unless you’re ready to select or add another one immediately. |
Server Settings
Block Outgoing Connections Firewall
Option | Description |
---|---|
Description | The description of the server appears in the Mail sidebar and any pop-up menu where you choose a server. |
User Name | Your user name on the mail server. |
Password | Your password on the mail server. |
Host Name | The name of the mail server. |
Automatically manage connection settings | Mail automatically manages settings for your email account in Mail, such as port numbers and authentication methods. If you deselect this option, you can specify the following, as directed by your email account provider:
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Advanced
Option | Description |
---|---|
TLS Certificate | Some SMTP servers require computers that connect to them to provide a certificate proving their identity. |
Allow insecure authentication | For accounts that don’t support secure authentication, let Mail use a non-encrypted version of your user name and password to connect to the mail server. |
See alsoVerify an email account’s outgoing server in Mail on Mac
You can edit the hosts file using terminal, although I'd not recommend it if you're unsure what you're doing. But doing so you can block outgoing access to specified IP addresses or websites.
Block Incoming And Outgoing Connections
If you simply want to stop your mac connecting out, why do you not simply turn off your wifi so you're not connected to the internet?
Mac App To View Outgoing Connections Email
Mac Check Outgoing Connections
Alternatively a GUI firewall like Little Snitch would be a better option as it gives you very granular options for blocking incoming/outgoing traffic and is fairly easy to use and set up.