Error : "The signup link does not appear to be valid."


I received an invitation to join the team ac-laia. I clicked on it and tried to register, but I got this error message “The signup link does not appear to be valid.”

OK, so I created an account. My gmail email address was refused, the platform wanted a “professional” email, whatever that is. I used another email, and this one was accepted. When asked what my organisation was, I typed “LAIA”.

It created a workspace for LAIA, which I have no use for, at least for the moment.

Now I can log into
But not into

How can I join my team, please?

If it’s “invitation only”, I should at least be able to send a message (“Hi, it’s me, I just had to use a different email to create my account”). Or I should be able to add another email to my profile.

What’s “unprofessional” about a gmail address anyway? Lots of professional people use them!

Hi Alain,

I’m not sure if we can help you with that. “” doesn’t seem to have anything to do with Mattermost, so you might have better luck getting in touch with the system administrator operating the mattermost instance there (if there is one available).
Maybe I also misunderstood your question, if so, please try to provide more details or rephrase it, thanks.

With regards to the “professional” e-mail:
This is also a setting the mattermost administrator of the given installation can configure, it looks like this and limits the available e-mail domains (most of the times, people allow only registrations from known domains which is a simple security measure to allow an open server to not be taken over by bot accounts with throw-away e-mail accounts):