It also depends on the content and subject line of your emails. I've used MailChimp before and I don't think things got sent to spam.
ActiveCampaign, Constant Contact or AWeber may be less likely to be sent to spam because they are paid platforms that more serious marketers use, but I can't say for sure. Personally I use ActiveCampaign and have never had problems with spam.
See this link from MailChimp:
[url=http://mailchimp.com/resources/guides/how-to-avoid-spam-filters/html/]How To Avoid Spam Filters[/url]
Edited by BenP (12/08/15 09:19 AM)