If you use GAE, you get a free plan on SendGrid (up to a max) and I've used it to send mails to gmail and yahoo accounts. Don't recollect anyone ending up in sp

If you use GAE, you get a free plan on SendGrid (up to a max) and I've used it to send mails to gmail and yahoo accounts. Don't recollect anyone ending up in spam but I haven't sent them in thousands. Will keep your comment in mind as I do so..