Google Workspace - blocking .htm, .html, .mhtml attachments. Do I need the .? (full stop)

[TwistedHelixis]

Just going back over a few security settings and I noticed that under Workspace > Gmail > Compliance > Attachment compliance we block .htm, .html, .mhtml

 

Now on the same page if you open Google list of built in file types you get this https://support.google.com/a/answer/2364580?hl=en-GB#file-types which does have the full stop

 

But some of their help pages and also this https://jamcyber.com/blog/cyber-insights/blocking-htm-html-attachments-in-google-workspace/ plus other sites and also Gemini just have htm, html, mhtml without the full stop.

 

Should I use a full stop or not?

Edited January 16 by TwistedHelixis

[TheHyperTechie]

I would say by looking at this information here, you need the full stop. You could test by adding .pdf, and then sending yourself one? this should rule it out.

[TwistedHelixis]

This is odd....

I have just added .url to the block list.

Then sent a test email with an attached website (.url) file and it doesn't get blocked with or without the full stop.

 

I'll give your .pdf idea a test and see if that gets blocked or not.

 

[TwistedHelixis]

9 minutes ago, HyperTech said:

I would say by looking at this information here, you need the full stop. You could test by adding .pdf, and then sending yourself one? this should rule it out.

 

On that page I notice it says the following..

Note: Although you can enter unsupported custom file types, they're matched only by filename, for example, document.sac

 

Does that mean that we can't block htm, .html, .mhtml .url attachments?

 

Although on the Workspace settings page it says.... Custom file types – Match files based on file name extension and doesn't mention needing a file name.

 

Ill send a pdf and see what happens.

[TwistedHelixis]

worked out it doesn't make a difference if you include the full stop or not.

 

The reason it wasn't working for my test, the server wasn't moving the email to the users Spam folder, which was the option selected. If I select reject as the option, it does reject the email and my test sending account then gets a rejected message delivered.

[TheHyperTechie]

1 minute ago, TwistedHelixis said:

worked out it doesn't make a difference if you include the full stop or not.

 

The reason it wasn't working for my test, the server wasn't moving the email to the users Spam folder, which was the option selected. If I select reject as the option, it does reject the email and my test sending account then gets a rejected message delivered.

Glad its working!