Setting up HTML signatures on OSX

Lately, I had to deal with the OSX mail app while trying to install some HTML signatures. It’s surprising to see that in 2017, there’s still e-mail clients that don’t accept HTML signatures. Thunderbird lets you pick an HTML file and you’re done, but with OSX’s mail app, things can get a bit difficult.


First of all, you’ll have to create your html signature: Make it the way you like, insert images, etc… Once you’re done, head to your Mac and fire up the Mail app, here’s where things get tedious:

Create a blank signature: This will be a placeholder, we just want the app to create a certain hidden file that we will later edit and include the HTML in.

Once the signature is created, save it and completely close the mail app: I can’t stress this enough: The mail app must be closed and not opened until the whole process is finished

Next, fire up the terminal and navigate to


and find the latest created .mailsignature file.

Open this file:

open -a textEdit CC820FFC-0F10-4D9E-8637-3D823E865F43.mailsignature

Then, replace everything inside the <body> </body> tags for the content inside the same tags from the signature you want to use, then save and close.

Finally, there’s a catch: Once you open the mail app, it will restore your previous signature, so you will have to lock the archive to prevent it from any further changes:

Do this with:

chflags uchg CC820FFC-0F10-4D9E-8637-3D823E865F43.mailsignature

And you’re done!!!! – or are you?

Well, mainly, for newer versions of the system (I think 10.7 onwards) this would be the method, but on older versions, you would have to do a couple of things different:

First, you’d have to go to


Note this time it’s V2 instead of V3.

Open your signature on Mac’s Safari and save it as a .webarchive file

Inside the Signatures folder you navigated to before, there would be a newly created .webarchive signatire: Yes, you guessed it right: You’ll have to replace this .webarchive file with the one you saved with Safari, keeping the filename and finally, lock it again so the mail app does’nt revert the changes:

chflags uchg CC820FFC-0F10-4D9E-8637-3D823E865F43.webarchive


After days banging my head trying to understand why any company would force their users to hop through these kind of loops in order to get a simple html signature, I only can come up with a thought: Why, oh, apple… why?!


Solving “ERROR: One or more PGP signatures could not be verified!” (Arch LINUX)

Arch linux adding PGP verification some years ago was a really good thing after realizing that perhaps, just downloading from any repository without any kind of verification was a bad idea.

The process for signing and managing keys for the official repos is pretty straightforward and automated, however, with AUR, this is quite different.

Sometimes, you can run into signature errors such as the following:

==> Validating source files with md5sums…
cower-16.tar.gz … Passed
cower-16.tar.gz.sig … Skipped
==> Verifying source file signatures with gpg…
cower-16.tar.gz … FAILED (error during signature verification)
==> ERROR: One or more PGP signatures could not be verified!
==> ERROR: Makepkg was unable to build cower.
==> Restart building cower ? [y/N]

This happens because your keys repository is lacking a certain key needed to authenticate a package authenticity.

If you edit the PKGBUILD, you might see (if the author followed the convetions) the needed key and the owner of such key.

For this example package (cower), the PKGBUILD had a line telling us the needed key corresponded to a maintainer called “Dave Reisner”.

After googling a bit, you can find a reference to this person’s pgp key here

In this page you can find the public key ID, which is “F56C0C53”

All you have to do is add this public key to your keys repository, and you’ll be good to go. No more PGP errors for packages maintained by this particular maintainer:

gpg –recv-keys F56C0C53

you can learn more about package signing on Arch’s magnificent wiki

netdata: The perfect real time monitoring tool

When you have to deal with lots of machines and their well-being is your responsability, you tend to use tools like nagios, centreon, or something alike.

However, for your day-to-day usage on single machines, it would be great and pretty useful to have a place to see all your system’s stats in order to find out those horrible bottlenecks that are locking your system or just to have a glipmse of how your system performs.

Netdata can do all that… and more… and how!

This is netdata’s top part, where you get a quick overview of your system load

It’s got many, many sections and it’s fully configurable, but here you have some captures of some parts of your system netdata monitors:


CPU Utilization


Disk Usage

TCP Connections

Network traffic


…and many more, all on your web browser when pointing at your machine’s ip:19999

You can install it from AUR on arch LINUX. It’s pretty straightforward. Install, start/enable systemd unit, and you’re good to go.

And here you have a live previeo on their official page: