biff command in Linux

If you're working on a Unix or Linux terminal and want instant alerts for incoming emails then the biff command is just what you need. Originally built for early Unix systems, biff is a lightweight terminal-based mail notification tool that instantly pops up when new mail arrives. It gets its name from a real dog at UC Berkeley, known for barking whenever the mailman showed up—fitting for a tool that does the same in your terminal

Unlike modern GUI email clients, which consume more resources and often delay alerts, biff works asynchronously through the comsat daemon, making it perfect for users working over SSH, managing remote Linux servers, or coding in minimal environments. It even shows the first few lines of the message directly in your terminal, giving you just enough info to decide if it's urgent—no switching windows or opening mail clients needed.

What is Biff?

Biff is like a text message notification for your Unix terminal – it pops up when you get new emails. Created for old-school systems without fancy GUIs, it’s named after a UC Berkeley dog that barked when mail arrived! 

Syntax:

biff [ y | n ]

Options:

• Y : This option is to enable the mail notification.
• N : This option is to disable the mail notification.

Note:

• When mail notification is enabled, the header and first few lines of the message will be printed on your screen whenever mail arrives. To enable the notifications you have to pass this command:

biff y

• Biff operates asynchronously via the comsat service. If that service is not enabled, biff will not do anything.
•  Turn Off Alerts of notification

biff n    # "No more distractions!"

How Biff Works

Here are how the biff works:

1. Comsat Service: Biff relies on the comsat (communications satellite) daemon—a background service that listens for new mail events. It acts like a notification server that pushes updates to your terminal instantly when a new mail arrives.
2. Asynchronous Alerts: Unlike GUI clients that interrupt your workflow or require you to switch windows, Biff alerts pop up in your current terminal session—while you're typing, compiling, or managing the server. No user action is needed.
3. Preview Feature: Biff doesn't just say "You’ve got mail." It smartly shows you the email sender and the first 15 lines of the message, allowing quick context without opening a mail client.

Biff vs Modern Tools

Biff is a classic Linux utility designed to notify users immediately when new mail arrives

Conclusion

The biff command in Linux may seem old-school, but it still holds a valuable place in modern terminal-based workflows, especially for system administrators, developers, or anyone using SSH on cloud servers like AWS, Azure, or GCP. It offers a fast, resource-light way to stay on top of your email—without disrupting your work or loading a heavy GUI.