MyBB Community Forums

Cant find anything, by searching Mybb wiki etc, on how, if possible, to send mass mailing with an attachment, so may not be possible.

Any idea/s ?

Although, not strictly an attachment, you could upload it to your server and link to it. I'm relatively sure that there is no way to attach to the mailing form.

Many mail servers will reject massed attachment emails because of the potential threat of it being virus spam.