Detect and block spam

[marien-probesys]

Follow-up of #645

Problem

Allowing open support (i.e. any user can open a ticket) can cause spam problems. The initial email server should already do a lot of stuff to prevent spam, but there are always possibilities that spam enters.

Ideas

I can see different options to prevent spam:

• Block email addresses: user cannot be created with this email
• Mark an email/ticket as spam: the ticket is totally hidden from the lists. This could also block the initial email address, and/or train a Bayesian filter
• Automatically detect spam based on mail X-Spam headers