Category: Tips

Here are some useful computer tips to improve performance, security, and productivity:

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How to format a Mac Drive in Terminal

Here is a few sample examples of how to format a drive in Terminal.

Click Applications > Utilities > Terminal.

Always run Diskutil list. This will show you the list of the drives on that computer which will help you identify which drive name is needed to for the DiskNoteID at the end of the terminal command.

Formatting a Disk to Mac OS Extended Journaled (JHFS+) from Terminal in Mac OS X

diskutil eraseDisk JHFS+ DiskName /dev/DiskNodeID

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What is Dkim for email and do I need it?

DKIM stands for DomainKeys Identified Mail.

It’s an email authentication method that helps prove an email really came from the domain it claims to be from—and that it wasn’t altered along the way.

Here’s the plain-English version:

  • When an email is sent, the sending mail server adds a digital signature to the message.
  • That signature is created using a private key owned by the sender’s domain.
  • The receiving mail server looks up the sender’s public key in DNS and checks the signature.
  • If it matches ✅ the email is legit and unchanged.
  • If it doesn’t ❌ the message may be spam, spoofed, or tampered with.
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What is SPF for email and do I need it?

SPF (for mail) stands for Sender Policy Framework.

It’s an email authentication method that helps stop email spoofing—basically, it tells the world which mail servers are allowed to send email on behalf of your domain.

How it works (plain English)

  1. A domain publishes an SPF record in DNS.
  2. That record lists the servers/IPs allowed to send email for the domain.
  3. When an email is received, the recipient’s mail server:
    • Checks the SPF record
    • Verifies whether the sending server is on the approved list
  4. If it’s not allowed, the message can be marked as spam, rejected, or flagged.
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macOS Big Sur Update 11.7.11

To update macOS Big Sur to version 11.7.11 (build 20G1443), which is the latest and final version of Big Sur (released February 2, 2026), follow these steps. Note that this is a very minor point release Apple made years after officially ending support for Big Sur in 2023. It mainly extends certificates so features like iMessage, FaceTime, and device activation keep working past January 2027 — there are no new security fixes beyond that.

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MacOS Catalina 10.15.8 update

macOS Catalina (version 10.15), originally launched in October 2019, marked a significant shift for Apple’s desktop operating system. It introduced features like Sidecar, Apple Arcade integration, the dedicated Music, TV, and Podcasts apps (replacing iTunes), enhanced security with Activation Lock, and the complete removal of 32-bit app support. After its final regular point update in 2020 (10.15.7), most users assumed Catalina had reached the end of its road, with Apple focusing on newer versions like Big Sur, Monterey, Ventura, Sonoma, Sequoia, and the current macOS Tahoe (version 26).

However, on February 2, 2026, Apple quietly released macOS Catalina 10.15.8 — more precisely labeled as macOS Catalina Security Update 2026-001 10.15.8 (build 19H2036). This update surprised many long-time Catalina users, as it arrived over five years after the previous point release.

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