a certain number of emails are going to end up in the spambox no matter what...regardless of who the sender is...be it from an individual, company, or email/newsletter service.........
Some email providers are far more aggressive than others when it comes to tossing shit in the spambox..........
The best way around this is actual individual "personal" conversational contact....which defeats the purpose of mass mailing your contacts.
I'm sure that
SM has taken steps to insure that their emails hit the most inboxes possible...........