The only time I remember being blocked from using a mailinator email it was a client side regex form validation - using one of Mailinator’s "alternate domains" got around that.
I would suspect that a lot of companies are willing to add a JS regex to their form validator, but are not willing to add SMTP headers sniffing to their validator. That barrier means that much of the time a simple domain name change will work.
The GPs comment is not unhelpful, and certainly not "Disinformation". It just isn’t completely reliable. Sometimes it will work, sometimes it won’t depending on how motivated the author of the validation is.
I would suspect that a lot of companies are willing to add a JS regex to their form validator, but are not willing to add SMTP headers sniffing to their validator. That barrier means that much of the time a simple domain name change will work.
The GPs comment is not unhelpful, and certainly not "Disinformation". It just isn’t completely reliable. Sometimes it will work, sometimes it won’t depending on how motivated the author of the validation is.