Mail.com not working in Basilisk Topic is solved

[Rocketeer]

In Basilisk, I cannot access Mail.com. By that, I do not mean simply that I can't log in. I am fully unable to access the site at all.When I attempt to go to Mail.com, I get the following error message:

Not Acceptable

An appropriate representation of the requested resource could not be found on this server.

Additionally, a 406 Not Acceptable error was encountered while trying to use an ErrorDocument to handle the request.

Mail.com works fine in all of my other browsers. I only get this issue with Basilisk, and I didn't always. It used to work fine until a few months ago, then the issue started and never went away.

Operating system: Windows 10 Pro 64-bit 22H2 (OS Build 19045.6332)
Browser version: 2025.07.04
32-bit or 64-bit?: 64-bit
Problem URL: https://www.mail.com/
Theme: Default
Installed add-ons: Cookie Masters, Greasemonkey for Pale Moon, Image Search Options, ImageHost Grabber, MozArchiver, Mozilla Archive Format, Sasuga (I installed it in an attempt to see if changing the browser's user-string would fix my Mail.com problem - it didn't work), Session Manager, Tab Groups, uBlock Origin (disabled), User Agent Status (disabled).
Installed plugins: OpenH264 Video Codec provided by Cisco Systems, Inc., Dragon Plugin (Installed after the Mail.com problem already existed), VLC Web Plugin, Java(TM) Platform SE 8 U461, Java Deployment Toolkit 8.0.4610.11,

[Moonchild]

Same happens in Pale Moon. They are discriminating against your browser and flat-out refusing connections.
I say: complain to mail.com

[Rocketeer]

Same happens in Pale Moon. They are discriminating against your browser and flat-out refusing connections.
I say: complain to mail.com

In the meantime and/or if they don't fix it, are there any workarounds? I tried some user-agent string changing extensions but they didn't help.

[Moonchild]

It's hard to find a workaround if we don't know what they are checking for, specifically. It's a server-side check of some sort.

[Rocketeer]

It's hard to find a workaround if we don't know what they are checking for, specifically. It's a server-side check of some sort.

I've contacted Mail.com support and I'm waiting for a reply. I'm not particularly hopeful that they'll do anything, but who knows?

[adoxa]

It does not accept any type of video. If you go to about:config, network.http.accept.navigation and remove ,video/x-matroska,video/webm (at least, that's what Basilisk has) it will work.

[Moonchild]

That's a nonsense check. The "Accept" header indicates what the browser accepts as a response type, not what a server would accept.

Also, Adoxa, what kind of voodoo investigative power do you have figuring that one out? XD

[adoxa]

"Copy as cURL". Just a matter of removing stuff until it works.

[Rocketeer]

It does not accept any type of video. If you go to about:config, network.http.accept.navigation and remove ,video/x-matroska,video/webm (at least, that's what Basilisk has) it will work.

It worked! After making that modification, I can now not only access Mail.com, but login.

[jobbautista9]

The content-type they return for 200 is text/html;charset=UTF-8. IIRC I think there needs to be a space between the MIME and the charset? It could be causing an issue server-side, though that still doesn't explain why video/* would cause the server to return a 406...

[Bilbo47]

Okay that worked in PM also, for loading the home page at least.
Anyway I tried that service the other year, and didn't stick with it - same as with several other competing services ... mainly because my calendar program does not speak CalDAV.

[Moonchild]

that still doesn't explain why video/* would cause the server to return a 406...

it's because mail.com does a server-side check on the Accept header and whomever wrote that check is blissfully unaware of what the header means.

[Moonchild]

I've been having a frustrating back-and-forth with mail.com's support department who seem to be absolutely adamant to not read the clear descriptions I've sent them of the problem and just completely ignore that we already found the exact cause. If they are actually more than form reply farms, then people are really not doing their job and not recognising when something needs to be forwarded and/or escalated to tech teams.

[ltcomdata]

It does not accept any type of video. If you go to about:config, network.http.accept.navigation and remove ,video/x-matroska,video/webm (at least, that's what Basilisk has) it will work.

And what sort of thing will break in the general browser for other websites if I do this --- because presumably, I cannot do this on a per-website basis?

[Moonchild]

Wasted way too much time talking to mail.com support who don't even acknowledge everything I explained, refuse to escalate it to tech heads who can do something about it and just default to "your browser is not supported, use one of these instead" in the end, fully ignoring specific explanations offered including the community analysis here in this thread.

fliptable.gif

[Moonchild]

And what sort of thing will break in the general browser for other websites if I do this

At the moment, not much. But since this is actively being discussed in the whatwg/fetch spec, it's likely in the long term that it may start interfering with video playback in the browser once it becomes standardized in mainstream. At which point mail.com will break for their "supported" browsers as well; at which point I bet it'll get fixed within an hour.