running an e-card service
assuming most users of this service will be sending to free based webmail such as hotmail I'm concerned on measures I should take to avoid all cards sent ending up in spam/junk mail folders even if they are not. (do things like SPF help?)
the e-mails will be sent out by php, is there anything that should be done in order to avoid being used for spam? I am considering a capcha style user verification before a card being sent out.
I'll be greatful to hear any helpful thoughts you might have about this subject.
