[plugin : Subscribe2] Emails not sent

Hi,

I’ve installed Subscribe2 on a website, but can’t get it to work : emails are not sent, neither automatic ones nor test emails.

Here is what I’ve checked so far :
– emails are sent from an adress on the same domain as the website
– “Restrict the number of recipients per email to (0 for unlimited)” : set on 1
– “Disable email notifications is checked by default on authoring pages?” : not checked
– I can access email sending logs on the server, and despites dozens of tests, no error message is displayed.

What more can I try ?
Thanks in advance
Corinne