E-Mail config doesn't allow adress

[Bzzz]

Hi,

setting up alerts via mail results in the following message: "Syntax error in parameters or arguments"
I've checked with another adress from the very same provider, works as it should.
So what's special about the first one I tried? It starts with a dot. Yes, that is possible

[hdsentinel]

E-mail address starting with a dot . ?

Yes, I'm sure that can cause problems

There should be no problems if there are dots in the email address - but if it starts with dot, there can be troubles.